Answer to question 1:
Adi Shankaracharya's devotional writings do not reflect any change in his philosophical position. In these writings he has spoken in a manner that is familiar to devotees who are not capable of following Jnana Yoga and need hand holding from the deities.
There exists three great misconceptions regarding Sankara's
philosophy, both in India and in the West. The first of these is that
he discourages the performance of duties and advocates the discipline
of non-action for the realization of the Truth.
...............
Secondly it is contended, specially in the West, that because of
Sankara's staunch loyalty to the Non-dualistic ideal of Brahman, or
the Absolute, he is an enemy of the gods and goddesses of the popular
religion. Undoubtedly he held the Ultimate Reality to be beyond name
and form and of the nature of Pure Consciousness. He also stated that
the direct method for realization of Brahman is not worship, but the
path of knowledge, which consists in hearing the instruction of a
teacher, reflecting on its meaning, and lastly, meditating with
single-minded devotion on Truth. Philosophical discrimination (viveka)
and renunciation of the unreal (vairagya) constitute for Sankara the
basic disciplines for realization of Brahman. Yet he was aware that
few aspirants are strong enough to climb this steep path. The majority
require a tangible symbol of Truth, anthropomorphic or otherwise, and
also a human relationship with a Personal God. For them prayer and
supplication form an indispensable part of worship. Out of compassion
for these seekers Sankara composed many hymns in praise of such
popular deities of Hinduism as Siva, Vishnu, and the Divine Mother. As
one reads these hymns, one is impressed by the magnanimity of Sankara,
who having attained the highest vision of the Absolute, brought
himself down to the level of ordinary worshippers smitten with the
idea of many transgressions, assumed their attitude of insignificance
and helplessness, and prayed to the Lord for grace to attain
liberation from the many miseries of earthly life. ...............
Even in his theistic hymns Sankara never permits one to forget that
Brahman alone is the foundation of all relative ideas and that the
effulgence of Pure Consciousness radiates through the vesture of name
and form. The devotee catches a glimpse of the Absolute through the
form of a Personal God, who is the highest manifestation of the
Infinite that a finite mind can comprehend on the relative plane.
Sankara reiterates the art of concentration through the worship of the
Personal God (Saguna Brahman) and acquires purity of heart through
performance of unselfish duties. Endowed then with concentration and
purity, he sets himself to the task of acquiring the Knowledge of
Brahman and realizes, the the end, the Impersonal Absolute. Sankara
initiated the worship of Sakti, or the Divine Mother, in his
monasteries.
Thirdly, it is said by some of Sankara's Western critics that he moved
away from the teachings of the seers of the Upanishads.
..................
Preface in Self-Knowledge (Atmabodha) by Swami Nikhilananda
Answer to question 2:
It is certainly true that Manisha Panchakam would appear to show a dramatic change in Sankaracharya's position regarding the caste issue. The problem is that not every scholar considers it to be an authentic writing of Sankaracharya. If you read the letter of Swami Vivekananda he mentions the contradiction in Sankaracharya's writing on caste but is silent on Manisha Panchakam. It would have beem natural to point out the U-turn in Manisha Panchakam but he remains silent.
(Translated from Bengali )
All Glory to God!
BARANAGORE, CALCUTTA, 7th Aug., 1889.
DEAR SIR,
................
I have certain questions to put, and you, sir, have a wide knowledge
of Sanskrit; so please favour me with answers to the following:
- Does any narrative occur about Satyakâma, son of Jabâlâ, and about Jânashruti, anywhere else in the Vedas excepting the Upanishads?2
**2. In most cases where Shankaracharya quotes Smriti in his commentary on the Vedânta-Sutras, he cites the authority of the Mahâbhârata. But
seeing that we find clear proofs about caste being based on
qualification both in the Bhishmaparva of the Mahabharata and in the
stories there of the Ajagara and of Umâ and Maheshvara, has he made
any mention in his writings of this fact?
**
3. The doctrine of caste in the Purusha-Sukta of the Vedas does not make it hereditary — so what are those instances in the Vedas where
caste has been made a matter of hereditary transmission?
- The Achârya could not adduce any proof from the Vedas to the effect that the Shudra should not study the Vedas. He only quotes
"यज्ञेऽनवक्लृप्तः" ("The Shudra is not conceived of as a performer of
Yajna or Vedic sacrifices.") (Tai. Samhita, VII. i. 1. 6) to maintain
that when he is not entitled to perform Yajnas, he has neither any
right to study the Upanishads and the like. But the same Acharya
contends with reference to "अथातो ब्रह्मजिज्ञासा", ("Now then
commences hence the inquiry about Brahman.") (Vedânta-Sutras, I. i. 1)
that the word अथ here does not mean "subsequent to the study of the
Vedas", because it is contrary to proof that the study of the
Upanishad is not permissible without the previous study of the Vedic
Mantras and Brâhmanas and because there is no intrinsic sequence
between the Vedic Karma-kânda and Vedic Janâna-kânda. It is evident,
therefore, that one may attain to the knowledge of Brahman without
having studied the ceremonial parts of the Vedas. So if there is no
sequence between the sacrificial practices and Jnana, why does the
Acharya contradict his own statement when it is a case of the Shudras,
by inserting the clause "by force of the same logic"? Why should the
Shudra not study the Upanishad?
The Complete Works of Swami Vivekananda, Volume 6, Epistles-(Second Series), VIII
I once asked a staunch Sankara folower as to what is the real position of Sankara on the caste issue given that he takes contradictory position in his Brahma Sutra and Upanishadic commentaries and in Manisha Panchakam. He told me that Sankara's commentaries on the Brahma Sutra and the Upanishads are authoritative and what he wrote in some obscure little text is of no value.