I will answer from Gaudiya Vaishnava perspective..
Since you seem have to issue with iskcon, I will quote from his authentic biographies and six goswamis who established gaudiya vaishnava theology.
What is the position of Durga?
The highly regarded book of Gaudiyas Brahma Samhita states:
sṛṣṭi-sthiti-pralaya-sādhana-śaktir ekā
chāyeva yasya bhuvanāni bibharti durgā
icchānurūpam api yasya ca ceṣṭate sā
govindam ādi-puruṣaṁ tam ahaṁ bhajāmi
BS 44: The external potency Māyā who is of the nature of the shadow of the cit potency, is worshiped by all people as Durgā, the creating, preserving and destroying agency of this mundane world. I adore the primeval Lord Govinda in accordance with whose will Durgā conducts herself.
Devi Dhama is described there which is material world and its presiding deity is Durga.
Thus, Durga is external energy or Bahiranga Shakti of Krishna.
Jiva goswami says the same in Tattva Sandarbha, text 33
The Lord does not interfere with the skillful actions of māyā, the controller
of the material world, who has been his devotee without beginning.
Desiring that the jīvas become favorable to him out of fear of māyā, the
Lord teaches:
My māyā, made of the guṇas, fit for the jīva’s pleasure, is hard to surpass,
but those who surrender to me alone can cross over this māyā. BG 7.14
The Lord, as ācārya, later teaches this particularly through his form of Vyāsa, a līlāvatāra. Vyāsa saw bhakti which destroys māyā (anarthas anarthopaśamaṁ).
Thus there are coordinated functions of the māyā and the Lord concerning
bewilderment of the jīva and desiring to make the jīva favorable.
“Māyā is a śakti and a śakti has ability to act. Śakti is merely a
quality. Why then does māyā have the particular quality of being
ashamed (if she is just an insentient śakti)?” Scriptures describe
that there are controlling deities of these śaktis. One should see the
discussion between Indra and Māyā (who is personified as a
person)[Uma] in Kena Upaniṣad. Now let us return to the topic.
In commentary to Bhag 11.27.29:
With offerings such as prokṣaṇa one should worship Durgā, Vināyaka, Vyāsa, Viṣvaksena, the spiritual masters and the various devas. All these personalities should be in their proper places facing the Deity of the Lord.
Jiva Goswami states that the names mentioned are not the wordly devas but eternal associates of Lord in Vaikuntha and he quotes from Padma Purana.
Thus, Durga name can also represent internal potency of the Lord.
Since, Gaudiya Vaishnavas worship Radha, who is primeval shakti, source of all laxmis and Durgas(a/c to Gaudiya Vaishnavism), they don't worship any other goddess. Worship is not prohibited, if done in the proper mood understanding them to servants of Krishna. Thus, you can say Gaudya Vaishnavas are also Shaktas because they worship Adi Shakti(Radha) along with Shaktimaan(Krishna).
The statements of non difference like "Krishna is Durga. Durga is Krishna. One who sees difference will not be be liberated", and "One should not see the difference between Brahma, Vishnu and Shiva" are explained by Jiva Goswami in Paramatma Sandarbha. He states that it means Durga, Shiva and Brahma are not independent manifestations, but they work under the will of Lord Vishnu only. Thus one should not see that they are independent agents. He quotes from Bhagavatama and other scriptures where clearly differentiation is made and Vishnu is stated to be superior. He also quotes statements which says one who thinks brama and Shiva are equal to Vishnu is a heretic.
Now coming to the portion where Sri Chaitanya is called by his followers as Durga. Shiva. Since, Gaudyas believe him to be incarnation of Krishna. The interpretation should be like this: in 10th chapter of gita, krishna says I am Garuda among birds, Vajra among weapons.. this means he is counting his opulences, that doesn't mean he is Vajra. One can interpret them similarly. Or another meaning there is no need to independently worship Lord Shiva because since all devas are just working under my will.
As Bhagavatam states:
SB 4.31.14: As pouring water on the root of a tree energizes the trunk, branches, twigs and everything else, and as supplying food to the stomach enlivens the senses and limbs of the body, simply worshiping the Supreme Personality of Godhead through devotional service automatically satisfies the demigods, who are parts of that Supreme Personality.
Bhagavatam also lists which deva can be worshipped to get which material desires and concluding verse rejects all the above things and just states:
SB 2.3.10: A person who has broader intelligence, whether he be full of all material desire, without any material desire, or desiring liberation, must by all means worship the supreme whole, the Personality of Godhead.
In Bhakti sandarbha, Jiva Goswami recounts story of previous life of Satyabhama wherein her father worshipped Surya but achieved Krishna, Jiva Goswami says it is because he worshiped him properly understanding him to be representation(servant) of Vishnu and also because of the effect of holy place. Otherwise worshippers of other devas don't attain Krishna.
Verses 307 to 318 from https://vedabase.io/en/library/cc/madhya/20/ gives us idea of position of devas where Chaitanya Mahaprabhu speaks to Sanatana Goswami:
Text 307: “Lord Kṛṣṇa, the Supreme Personality of Godhead, expands a portion of His plenary portion and, accepting the association of the material mode of ignorance, assumes the form of Rudra to dissolve the cosmic manifestation.
Text 308: “Rudra, Lord Śiva, has various forms, which are transformations brought about by association with māyā. Although Rudra is not on a level with the jīva-tattvas, he still cannot be considered a personal expansion of Lord Kṛṣṇa.
Text 309: “Milk is transformed into yogurt when it associates with a yogurt culture. Thus yogurt is nothing but milk, but still it is not milk.
Text 310: “ ‘Milk changes into yogurt when mixed with a yogurt culture, but actually it is constitutionally nothing but milk. Similarly, Govinda, the Supreme Personality of Godhead, assumes the form of Lord Śiva [Śambhu] for the special purpose of material transactions. I offer my obeisances at His lotus feet.’
Text 311: “Lord Śiva is an associate of the external energy; therefore he is absorbed in the material quality of darkness. Lord Viṣṇu is transcendental to māyā and the qualities of māyā. Therefore He is the Supreme Personality of Godhead.
Text 312: “ ‘The truth about Lord Śiva is that he is always covered with three material coverings — vaikārika, taijasa and tāmasa. Because of these three modes of material nature, he always associates with the external energy and egotism itself.’(SB 10.88.3)
Text 313: “ ‘Śrī Hari, the Supreme Personality of Godhead, is situated beyond the range of material nature; therefore He is the supreme transcendental person. He can see everything inside and outside; therefore He is the supreme overseer of all living entities. If someone takes shelter at His lotus feet and worships Him, he also attains a transcendental position.’ (SB 10.88.5)
Text 314: “For the maintenance of the universe, Lord Kṛṣṇa descends as His personal plenary expansion in the form of Viṣṇu. He is the director of the mode of goodness; therefore He is transcendental to the material energy.
Text 315: “Lord Viṣṇu is in the category of svāṁśa because He has opulences almost equal to Kṛṣṇa’s. Kṛṣṇa is the original person, and Lord Viṣṇu is His personal expansion. This is the verdict of all Vedic literatures.
Text 316: “ ‘When the flame of one candle is expanded to another candle and placed in a different position, it burns separately, and its illumination is as powerful as the original candle’s. Similarly, the Supreme Personality of Godhead, Govinda, expands Himself in different forms as Viṣṇu, who is equally luminous, powerful and opulent. Let me worship that Supreme Personality of Godhead, Govinda.’ (bRAHMA sAmhita 5.46)
Text 317: “The conclusion is that Lord Brahmā and Lord Śiva are simply devotee incarnations who carry out orders. However, Lord Viṣṇu, the maintainer, is the personal feature of Lord Kṛṣṇa.
Text 318: “[Lord Brahmā said:] ‘I am engaged by the Supreme Personality of Godhead to create. Following His orders, Lord Śiva dissolves everything. The Supreme Personality of Godhead in His form of Kṣīrodakaśāyī Viṣṇu maintains all the affairs of material nature. Thus the supreme controller of the three modes of material nature is Lord Viṣṇu.’(SB 2.6.32)
Chaitanya Mahaprabhu also says:(from Padma Purana)
https://vedabase.io/en/library/cc/madhya/25/80/
yas tu nārāyaṇaṁ devaṁ
brahma-rudrādi-daivataiḥ
samatvenaiva vīkṣeta
sa pāṣaṇḍī bhaved dhruvam
‘A person who considers demigods like Brahmā and Śiva to be on an equal level with Nārāyaṇa is to be considered an offender, a pāṣaṇḍī.’
As some one quoted above,
isvaratve bhed maanile hay aparadh/ ek i iswar bhakter dhyan-anurup(2/9/139-42)
If you see the context of the words, Chaitanya is talking only about Krishna and his direct incarnations like Narayana, Rama etc.. And also Chaitanya himself distinguished even among those incarnations, the actual context of the verse is that: just to satisfy the person to whom Chaitanya was speaking, he spoke this to avoid tension in the speech and to have common ground that all other Vaishnavas also accept.
Thus overall Gaudiya Vaishnava theology states Krishna is Supreme and Maha Vishnu, Rama others are his direct incarnations and are thus in same category of Krishna who can be worshipped. Other devas are servants of Krishna/Vishnu.
I recommend you to study commentaries of prasthana trayi of Gaudya Vaishnavas, Gita, Vedanta Sutra and Upanishads. And also the works of 6 goswamis whom Chaitanya Mahaprabhu instructed to establish Gaudya Vaishnava school theologically. No where will you anyone other than Vishnu/Krishna established as supreme. The equality of Shiva and Vishnu etc.. is clearly rejected in all theological works. I think here, people are more eager to push their views in the name of Chaitanya Mahaprabhu by cherry picking one out of context to push one's own ideas and thus you will get only distorted version .
Or you can read Sat Sandarbhas of Jiva Goswami from https://archive.org/details/@vedantist?sort=creatorSorter&&and[]=subject%3A%22Srila%20Jiva%20Goswami%22.
If you have problem with ISKCON's demigod word, just use god or deva, it doesn't make any difference to theology.
Are the various devatas manifestations of aspects of the Supreme God or are they subservient to the Supreme God, as is the view in orthodox Gaudiya Vaishnavism?
All other devas are subservient to Supreme God. That is clear cut if you read primary sources of Gaudiya Vaishnavism. There is nothing to be confused at all in this point.
“What is the value of a throne to Lord Kṛṣṇa? The masters of the
various planetary systems accept the dust of His lotus feet on their
crowned heads. That dust makes the holy places sacred, and even Lord
Brahmā, Lord Śiva, Lakṣmī and I Myself, who are all portions of His
plenary portion, eternally carry that dust on our heads.”(SB 10.68.37)
Further Additions:
If you just look at the context where Chaitanya took the form of Chandi and people offered prayers.
keha pade laksmi-stava, keha candi-stuti
sabe stuti pade yahara yena mati//CB, Madhya 18.166//
Some recited prayers to Laksmi, and some offered prayers to Durga.
Everyone offered prayers according to their realization.
Which means, Seeing Sri Gaurasundara in the dress of a sakti, or consort, persons who were situated in false egos of goodness began to pray to Him as
Narayani-Maha-Laksmi. Others who were situated in false egos of ignorance offered Him the prayers known as Candika-stotra.
And as Chaitanya said don't disrespect any deva.. The meaning is don't disrespect it doesn't mean that you have to say that a particular deva is equal to Vishnu and Chaitanya himself condemning saying that others are equal to Vishnu.
sivera gaurava bujhayena gauracandra
eteke sankara-priya sarva bhakta-vrnda//CB, Antya 2.242//
In this way Gauracandra revealed the glories of Siva. That is why
Sankara is dear to all the devotees.
na mane caitanya-patha bolaya `vaisnava'
sivere amanya kare vyartha tara saba//CB, Antya 2.243//
The endeavors of one who does not follow the path of Lord Caitanya and
disrespects Siva yet claims to be a Vaisnava are all useless.
The meaning is no follower of Chaitanya should disrespect Lord Shiva understanding his position as supreme Vaishnava.
As Bhagavatam states:
(12.13.16) it is stated:
nimna-ganam yatha ganga
devanam acyuto yatha
vaisnavanam yatha sambhuh
purananam idam tatha
“Just as the Ganga is the greatest of all rivers, Lord Acyuta the supreme
among deities, and Lord Sambhu [Siva] the greatest of Vaisnavas, so
Srimad Bhagavatam is the greatest of all Puranas.”
Those who disrespect the guna-avatara Mahadeva do not actually follow
Sri Caitanya. Veteran Vaisnavas headed by Sri Anandatirtha worshiped the
guna-avataras Brahma and Siva as devotees of the Supreme Lord. Sri
Krsna Caitanya visited the temple of Siva, the incarnation of a devotee,
and prayed for devotional service to Krsna.
Siva is the best among the twelve
Vaisnava authorities(as per Bhagavatam); and he is the original spiritual master of the
Visnusvami-sampradaya.
In the Srimad Bhagavatam (4.24.28) Lord Siva speaks the following
words:
yah param ramhasah saksat
tri-gunaj jiva-samjnitat
bhagavantam vasudevam
prapannah sa priyo hi me
“Any person who is surrendered to the Supreme Personality of Godhead,
Krsna, the controller of everything—material nature as well as the living
entity—is actually very dear to me.”
And in the Srimad Bhagavatam (4.4.13-14) Sati speaks as follows:
“It is not wonderful for persons who have accepted the transient
material body as the self to engage always in deriding great souls.
Such envy on the part of materialistic persons is very good because
that is the way they fall down. They are diminished by the dust of the
feet of great personalities.
“My dear father, you are committing the greatest offense by envying
Lord Siva, whose very name, consisting of two syllables, si and va,
purifies one of all sinful activities. His order is never neglected.
Lord Siva is always pure, and no one but you envies him.”
If you read works of Six Goswamis, you will clearly understand the Gaudiya Vaishnavism. If you read the Chaitanya biographies, you will understand practically how to respect other devas as Chaitanya revealed by his actions etc.(that doesn't mean you say all are equal) and thus you can remain mature.
Thus, mature Gaudiya Vaishnavas though clearly say and know that Krishna is supreme and all others are servants of Krishna, don't disrespect any deva understanding them to acting as per the will of the Lord and their respective positions.
As Chaitanya Charitamrita clearly puts:
https://vedabase.io/en/library/cc/adi/5/
Text 140: “Who is this mystic power, and where has she come from? Is
she a goddess or a demoness? She must be the illusory energy of My
master, Lord Kṛṣṇa, for who else can bewilder Me?” (quoted from
Bhagavatam)
Text 141: “What is the value of a throne to Lord Kṛṣṇa? The masters of
the various planetary systems accept the dust of His lotus feet on
their crowned heads. That dust makes the holy places sacred, and even
Lord Brahmā, Lord Śiva, Lakṣmī and I Myself, who are all portions of
His plenary portion, eternally carry that dust on our heads.” (quoted
from Bhagavatam)
Text 142: Lord Kṛṣṇa alone is the supreme controller, and all others
are His servants. They dance as He makes them do so.
Gopala Bhatta Goswami, one of the six goswamis gives the meaning of BG 9.23 as follows:
ye 'py anya devata bhakta
yaj ante sraddhayanvitah
te'pim am eva kaunteya
yajanty avidhpi- urvakam
This verse may be interpreted in three ways.
One meaning is this:
'My faithful devotees (from initiation to the point of death) who
occasionally worship the devatas disregarding the forbiddance,
actually worship Me alone with great determination, not the devatas.
This is indicated by the word 'eva' which means that they really
worship only Me. By worshipping Me alone, realizing they are servants
and I am to be served, they become free from the cycle of birth and
death.
A second meaning is as follows:
'All those who are not my devotees, filled with material desires
(sraddhayanvita) worship devatas with great determination to achieve
material results quickly. They worship Me in this way, thinking the
devas independent and equal to Me! They are not actually
worshipping Me at all! 0 son of Kunti, Arjuna, the prescribed process
is to hear about Me, chant My names, remember and worship Me. By this
alone can one be freed from the bondage of birth and death in this
material world. All other works such as worshipping devas,
sacrifice, charity etc. are prohibited, because, being temporary they
are the cause of the repeated cycle of birth and death. Therefore
worship of Me is the best activity. Apart from this, there is no path
to deliver oneself from the bondage of the material world, even for
Brahma and Indra who have attained immortality by drinking nectar.
What, then, to speak of mortals.
The same verse may be interpreted in a third way.
'Those worshippers of devas, bewildered by My external potency,
from their birth become Saiva, Sakta, Saura, Ganapatya etc. Later by
the instructions of a bonafide spiritual master and the association
of Vaisnavas they worship Me alone with extreme faith
(sraddhayanvita), with no other shelter. They certainly become My
devotees by the effect of My bhakti. But they must not worship with a
material motive (avidhi purvakam). To worship Me and at the same time
to worship devatas is called avidhi Leaving aside such worship, a
person must be dedicated to Me fully, without worshipping the devatas
even in dreams. In that pure condition, that person becomes My
devotee.'
What is forbidden above is of course independent worship of anya devas, and Gaudiya authors don't always mention that point explicitly.
Gopala Bhatta goswami then explain 6.9.22 of bhagavatam.
Other than devotional service to the Supreme Personality of Godhead,
everything is perishable or impermanent, and should therefore be abandoned. In
Srimad Bhagavatam 6.9.22 it is said:
avismi tam tam paripurna kamam svenaiva
labhena samam prasantam
vinopasarpaty aparam hi -balisah
sva langulenati titarti sindhum
"Free from all material conceptions of existence and never wonder
struck by anything, the Lord is always jubilant and fully satisfied by
His own spiritual perfection. He has no material designation, and
therefore He is steady and unattached. The Supreme Personality of
Godhead is the only shelter of everyone. Anyone desiring to be
protected by others is certainly a great fool who desires to cross the
sea by holding the tail of a dog."
Those who are situated in varna and asrama and do not worship the Supreme
Lord Govinda, but superficial devatas, are greatly foolish. What are the qualities
of Govinda? He is always satisfied by the perfection of His eight kinds of opulence
called anima, laghima etc. He alone awards the surrendered souls their desired
goal. Therefore, other than Him, no one else is fully satisfied.
Lord Govinda is 'avismita,' because being eternal, there is no question of
wonder in Him. He is 'prasanta,' because He has a form desired by His devotees.
Bewildered by the external potency of the Lord, a person leaves the devotional
service of the Supreme Lord and worships devatas. He is foolish; he is described
as a foolish man trying to cross the ocean by holding the tail of a dog. Thus, one
who has turned his face from the Lord to serve devas to fulfill his
insignificant desires gets no result, as everything is dependent on the Supreme
Lord. He has no way to escape from the bondage of repeated birth and death."
There are innumerable statements in works of 6 goswamis in support of what I said. Though Gaudiya Vaishnavas should not envy other devas or criticize them, they have made their position extremely clear i.e Krishna/Vishnu is the only lord, all other devas are subservient to him. If in a police station, if you say constable as constable and IG as IG, that is proper respect, but if you call constable as IG, that is not respect, in fact you make constable feel embarrassed by doing so.
Worshipping Shiva and other devas:
Here is further addition from Bhakti Sandarbha where Jiva Gowami says Brahma and Siva can be worshipped as devotees of Vishnu.
Brahmā, the original devatā, the instructor of bhakti for the world,
situated on his lotus, considered how to carry out creation. He could
not attain the knowledge by which the universe could be created. SB
2.9.5
Thus Mārkaṇḍeya speaks to Śiva:
varam ekaṁ vṛṇe 'thāpi pūrṇāt kāmābhivarṣaṇāt
bhagavaty acyutāṁ bhaktiṁ tat-pareṣu tathā tvayi
I request one benediction from you, who are full of all perfection and
able to shower down the fulfillment of all desires. I ask to have
unfailing devotion for the Supreme Lord and for his devotees,
especially you. SB 12.10.34
I ask for devotion you (tvayi), since you are dedicated to the Lord.
Persons criticize you as a ferocious, violent person obsessed with the
cremation grounds and engaged in flirting with Umā, though you are
engaged in intense austerity and your feet are the object of
meditation by the best of ātmārāmas. Devoid of shame, they do not know
your pastimes.
SB 8.7.33
O Lord! By association with your dear friend Śiva, we have today
attained you, the best remedy for birth and death, which are difficult
to cure. SB
4.30.38
If one thinks that Śiva, the devotee, is equal to Viṣṇu, one does not attain bhakti. It is rather a sin. In Vaiṣṇava-tantra it is said:
Fools who concentrate their minds and see Viṣṇu on the same level as
other persons do not attain pure bhakti to the Lord. He who sees Viṣṇu
to be equal to Brahmā and Śiva is certainly a pāśāṇḍi.
These statements of non-difference with Viṣṇu are for śānta-bhakti-jñānīs. For
instance, Śiva states in the story of Mārkaṇḍeya:
brāhmaṇāḥ sādhavaḥ śāntā niḥsaṅgā bhūta-vatsalāḥ
ekānta-bhaktā asmāsu nirvairāḥ sama-darśinaḥ
sa-lokā loka-pālās tān vandanty arcanty upāsate
ahaṁ ca bhagavān brahmā svayaṁ ca harir īśvaraḥ
The inhabitants, the ruling devatās of all planets, Brahmā, the
SupremeLord and I, glorify, worship and assist the saintly brāhmaṇas,
who are peaceful, free of material attachment, compassionate to all
living beings, purely devoted to us, devoid of hatred and endowed with
equal vision.
These devotees do not differentiate between Viṣṇu, Brahmā and me, nor
do they differentiate between themselves and other living beings. But
surpassing that conception we worship you pure Vaiṣṇavas. SB
12.10.20-22
Surpassing them (tat), we worship you--Mārkaṇḍeya and others, who are pure
Vaiṣṇavas.
Śiva speaks to the Pracetas:
You devotees are dear to me just as the SupremeLord is dear to me. The
devotees hold me dear, just as they hold the Lord dear. SB 4.24.30
O gentle Bhavānī! When one performs benevolent activities for others,
the SupremeLord is very pleased. And when the Lord is pleased, I am
also pleased, along with all other living creatures. Therefore, let me
drink this poison. May all the living entities have auspicious
existence because of me! SB 8.7.40
Śiva describes Mārkaṇḍeya as a pure Vaiṣṇava:
Surely this saintly brāhmaṇa does not desire any benediction, not even
liberation, for he has attained pure devotional service unto the
inexhaustible Lord. SB 12.10.6
Because Śiva appeared in his heart Mārkaṇḍeya speaks of Śiva as non-different
from the Lord when his samādhi breaks. (SB 12.10.13) In the end Śiva
distinguishes the Lord from himself.
Difference of the Lord from Śiva is also stated in SB 1.2.24.
Smoke is superior to dull wood, and fire, sacred to the Vedas, is
superior to smoke. Similarly rajas is superior to tamas, and sattva is
superior to rajas, since it is favorable for realizing the Lord.
Śiva also says:
The person who desires to see me (Śiva) or Brahmā should first see
powerful Vāsudeva. Brahma Purāṇa 226.46
This means that by knowing the Lord all others are known. Śiva should be
worshipped as a Vaiṣṇava. If one has to worship Śiva in some circumstance,
some Vaiṣṇavas say that one should worship the Lord within Śiva’s form.
There is a story in Viṣṇu-dharmottara. A great devotee brāhmaṇa named
Viśvaksena wandered about the earth. One day he entered the edge of a forest.
The son of the village leader came and said to him, “Who are you?” When the
brāhmaṇa identified himself, the son said, “Today my head hurts. I cannot
worship Śiva, my worshipable deity. You do the worship in my place..
The brāhmaṇa answered. I am a brāhmaṇa dedicated to Viṣṇu. I should
worship only Viṣṇu. I worship no one else. Therefore go away quickly.
Viṣṇu-dharma 3.354.12-13
When he said this, the son raised his sword to cut off his head. The brāhmaṇa,
considered it not desirable to die by his hand said, “I will go there.” Going there,
he thought in his mind, “Because he increases ignorance, for this reason, Śiva is
in tamoguṇa. Nṛsiṁha should appear here to stop the worship of Śiva since
ignorance can be broken with eradicationof Śiva’s associates, just as the sun
rises and with its rays destroys ignorance. I will worship Nṛsiṁha in the Śiva
deity since Śiva’s worshippers have worshipped him in this form.” Taking a
handful of flowers he said “I offer respects to Nṛsiṁha.” The son of the village
leader raised his sword in anger. Suddenly the liṅga split and Nṛsiṁha appeared
and killed the son with his followers. There is a Nṛsiṁha deity in the south
named Liṅga-sphoṭa.
Thus the devotees worship Śiva as a Vaiṣṇava and some worship Viṣṇu in the
Śiva deity.
Attaining the Lord by independent worship of devatās is denied in Gītā:
Those who are devoted to other gods and with faith worship them,
worship me by the wrong method, O son of Kuntī.
I am the enjoyer and master of all sacrifices. Those who do not know
me as such continue to take birth.
The worshippers of the devatās go to the devatās, and the worshippers
of the Pitṛs go to the Pitṛs. The worshippers of ghosts go to the
ghosts, and worshippers of me come to me. BG 9.23-25
Some good qualities arise by worshipping the followers of the Lord (devatās). It is also an offense to disrespect them.
The disciple should learn to have faith in the Bhāgavatam, without
criticizing other scriptures. He should learn to avoid sinful acts of
mind, speech and body, to speak the truth and to control the mind and
external senses. SB 11.3.26
Padma Purāṇa says:
The supremeLord should always be worshipped. One should not disrespect
Brahmā, Śiva and others.
Gautamīya-tantra says:
If a person who worships Kṛṣṇa criticizes the devatās whatever dharma
he has accomplished is destroyed, what to speak of attaining dharma in
the future.
May Hayagrīva protect me from disrespecting the devatās when going on
a path. SB 6.8.17
It is a great fault to disrespect Śiva. Nandīśvara gave a curse in the Fourth Canto:
The curses are suitable because he takes ignorance in the form of
karma as knowledge, and he is foolish. Let those who follow Dakṣa, who
insulted Śiva, take repeated birth and death in this world. SB 4.2.24
Disrespecting Śiva is an offense because Śiva is a great devotee of the Lord.
Because you have in anger killed many Yakṣas, killers of your brother,
you have offended Kuvera, the brother of Śiva. SB 4.11.33
Remembering Kuvera’s friendship with Śiva (devotee of the Lord), Dhruva
prayed to Kuvera for bhakti, since he desired the devotee’s nature of being
respectful to all beings and desired bhakti. Thus it is said:
He who worships me constantly with pure devotion but criticizes Śiva
goes to hell for certain. Kūrma Purāna
This principle is also seen in the story of Citraketu. Kapila condemned
disrespecting ordinary living beings, what to speak of Śiva.
I, the soul of all beings, am always situated in all beings. He who
disrespects me in all beings performs false worship of my deity form.
SB 3.29.21
With one answer, you will not get full perspective, there are too many subtle points, but I just gave pointers. When you are theologically strong, you will understand Chaitanya biographies much better.
