2. I am not sure what you mean by Rishi continues to call him zudra..? Raikva accepts the daughter of janasruti and teaches janasruti the saMvarga/prAna vidhya, how everything in this Universe goes back to vAyu. One who learns no longer is a zudra. If you give specific reference of verses, it will help me to have a better understanding.
Reply: In verse 4.2.5 Raikva
continues to call Janasruti a sudra. According to your interpretation, since Janasruti has now offered his daughter to Raikva, “Raikva accepts it now as he understood that King Janasruti valued the learning as his life”. From that perspective, since as you said “A Zudra does not understand the importance and value of learning. Jana-sruti acted like the zudra, without understanding the value of learning he wanted to achieve and tried to buy that learning with material wealth”, with the gift of his daughter, Janasruti’s sudra-hood would no more be there, so it would have been superfluous for the Rishi to call him so repeatedly.
Moreover, at the conclusion the Sruti emphasises the villages given by Janasruti to raikva (and no more mention of his wife) which again indicates the significance of the material wealth in the 'transaction'.
3. You are right that sage Yajnavalkya says in Janaka's court that he bows to the best scholar in the court but wish to have the thousand cows from Janaka. But that's a debate between scholars of Janaka's court, where Yajnavalkya answers questions of Janaka and Asvala.
In Raikva's case, Jansruti wants to be a disciple of Raikva and asked him to teach the knowledge that Raikva acquired. In Yajnavalkya's case, Yajnvalkya answers specific questions asked by Asvala and Janaka.
Raikva - Janasruti is teacher teaching student. Yajnavalkya-Asvala-Janaka and his courtiers is PhD viva.
Reply: I gave two instances. There is an instance where Yajnavalkya visits Janaka (and it is mentioned that Yajnavalkya has given Janaka a boon that he may ask him any number of questions, and Yajnavalkya does give him Brahma jnanam, so the relationship of Janaka with Yajnavalkya is tantamount to disciplehood) and Janaka asks him “have you come for cows or for asking questions” and Yajnavalkya replies, he wants both, without waiting to call Janaka a sudra
Even in the instance you mentioned, king Janaka expressly states that the material wealth (in the form of cows), is for anyone who reveals his Brahmishtatvam. The cows are an enticement or reward, and Yajnavalkya proactively takes them away and later
in the course of the debate, shares his learning on Brahman, essentially the same knowledge that the Sruti repeats later on, with everyone present at the sadas,
including king Janaka. The point is clear – Brahma jnanam can be traded off with material wealth, and the fact doesn’t seem to degrade king Janaka into a Sudra.
4. Sukha in some puranas, follows Asrama dharma with four sons and a daughter.
Reply: Yes, there is a differing version in the Devi Bhagavatam. But while the Devi Bhagavatam is a much edited text (it contains much recent material like Tantric rites and Radha worship), there is a lot of disconnect between the stories of Suka in the Mahabharata (the oldest and most popular of them all) and the Devi Bhagavatam version. Devi Bhagavatam is considered a Shakta sectarian purana, while the Mahabharata is an ithihasa revered by all sects.
Even his father Rishi Vyasa became a Sannyasi without going through the chaturtha asramas. Though later, under the insistence of his mother, he entered into a relationship with the wives of Vichitravirya, that was more for the sake of continuing the Kaurava lineage, than due to any desire for Garhasthyam or for continuing his own line.
5. I am not saying the story on Sankara happened or not. But going from brahmacharya to samnyAsa asrama is influence of buddha (in my view). It's a later day addition.
Reply: In my view, both Pravritti and Nivrutti dharmas held power in society since the upanishadic times. You would find echoes of their mutual conflict in the Mahabharata Santhi and Anusasana parvas and in the Ramayana, parts of which are much older than Buddha.
I am not reproducing here the arguments of Sankaracharya and others on why Sannyasa is actually Athyasrama. But IIRC they trace it to certain passages from the older Upanishads like Brih Up 4.4.22 which strongly advocate a mendicant life. There are other Sannyasa Upanishads like Jabala Up which are considered quite old.
Jainism is a religion much older than the Buddha, and they too had a big role in spreading through their stories this idea of Sannyasa as something that transcends Varnasrama.
On the other hand, many examples can also be quoted from the upanishads for supporting your view, that the Rishis lived in Garhasthyam. So I think, it is a choice ultimately left to the individual. I think the Brahma Sutras advance some views on this topic but am not able to recall much from memory.
