Did he actually did this as given the above paragraphs?
Now, this is a purely historical question and which i am not answering.
I will be answering only two of your questions that can be addressed from scriptures.
Suppose a Guru chants a mantra (his Ishta mantra in this case) loudly addressed to a mass gathering. Does that mean that all who gathered there are initiated into that mantra?
First of all,
Mantra Diksha is much a more elaborate process than the mere transfer of mantra, which in technical terms, is known as the
Also, a Diksha is an one-to-one process and not one-to-many one,
Loosely speaking, Mantra Upadesa+ Shaktipata+ Abhisekha = Mantra Deeksha if we abide completely by Scriptures.
So, in this case we can rule out a full-fledged Diksha rather we can concentrate on only Upadesam.
But, even for Upadesam, a whole lot rules are there to be followed. I am giving few of them below:
Before initiating the Guru should tie the Sikha (tuft) of the disciple and then something of this sort happens:
...tatah sishyashya sirasi hastam datvA deyamantramashtottarasatam
japTa amukmantran teham dadAmiti shishyahaste jalam dadyAt...
...Thereafter, the Guru should the touch the disciple's head with his
hand and chant the mantra (which is to be given) 108 times and upon
saying "amuk mantra teham dadAmi (i am giving this mantra to you)"
shall pour water into the disciple's hand, and the disciple should
then say "dadaswa" which shows the approval (or acceptance) of the
Next, from Vashishta Samhita:
Tatah RishiAdisamyuktam Mantram Gururdakshina karne Trih SrAvayitvA
VAma karne Sakrit SrAvayet.
Thereafter the Guru should speak the mantra, along with Rishi, Devata
and other Nyasas, 3 times in the disciple's right ear and 1 time in the
left (vAma karne Sakrit).
The Gautamiya Tantram also repeats the same procedure:
Nyasa jalam tasya dehe Guruh samnyasya jatnatatah | Daksha karne Vaden
Mantram TrivAram PurnamAnasaha || Dakshe Iti DvijAtivishayam..
The Guru should do Nyasas with care on the disciple's body and speak
mantra into his right ears three times. (This rule of speaking unto
the right ear is only for the DvijAs).
So, Diksha involves the Guru chanting the mantra into disciple's right (or left ear) depending on the varna of the disciple. But, when a mantra is said out loudly (and publicly) this requirement is obviously not met.
From Bhairavi Tantram:
Daksha Karne Triso VidyAm EkorchArena ChocchAret |
DvijAtinAm Stri SudrAnancha VAmatah ||
The Guru shall speak the mantra into the disciple's right ear 3 times
and into his left ear 1 time. This is the rule for the Dvijas, for
women and Sudras it's just the opposite i.e 3 times in the left ear
and 1 time in the right.
Same has been repeated in the Rudra YAmala Tantram:
Gurustu PrAngukhobhutva ShishyA Prachi Mukha Stithah |
Dakshine Karne VAme chaiva TathA Sakrit ||
Viparitam Tato Geyam
StreesudrAnancha VAmatah |
Guru should face the east and the disciple the west direction. Guru
should then speak the mantra into disciple's right ear 3 times and left
ear 1 time. For Sudras and women the process will be reversed.
So, in a so called, one-to-many, mass initiation, none of these requirements are met. So, what happened can not be called Diksha technically. May be something else, like Satsang etc, but not Diksha.
Can Sudras be initiated into pranava (OM)?
I'm planning to post a separate question-answer on this topic based on Agamas only.
For the time being, i present only one verse from the Devi YAmala which answers the question in the negative.
SwAhA Pranava Samyuktam Sudre Mantram Dadad DvijAh |
Sudro NirayagAmi SyAd BrAhamano YAtyadhogatim ||
The Brahmin who gives to a Sudra a mantra that has the pranava (OM) and swaha in it goes himself downwards and the Sudra too visits hell.
Devi YAmala Tantram
Apart from all these there occurred another Dosha, that of "Guru Mantra Prakasha" or revealing one's Guru Mantra publicly which is strictly not to be done.
Even Ramanuja's Guru advised him to conceal the mantra as one can see. And, every Guru does the same, it's common.
This is what Lord Shiva says to Mother Goddess on this topic:
Gurum prakAshayed dhimAn mantram yatnen gopayet |
prakAshAbhyAm nasyatah sampadAyushi ||
The Guru must always be revealed by the wise, but the mantra must
carefully be kept secret. By not doing these two acts- that is, by not
revealing the Guru and by not concealing the mantra, decrease,
respectively, [the disciple's] wealth and longevity.
Kularnava Tantram 11.88