Very well written and thought provoking piece as always JAMi!
In general, I firmly believe that a mother has the utmost right to be respected and obeyed (unless the order is to sin) by her children. This is not conditional; even if the mother is harsh and unreasonable, there is no other option but to respect her. A child can reason with her, but within limits of politeness and respect. I'm ofcourse speaking in the ideal sense. This is why I respect Suraj's character, as he is quite close to this ideal.
Now this may not seem to answer your question, but really it does. If every mother has the right to have dutiful children, then Bhabho too deserves an ideal son like Suraj.
As for the historical truths revealed by Babasa, I think there is another way to look at these. Why did Suraj lie about him failing in school? Isn't it obvious? He knew that if he didn't there is a high chance that Bhabho would not have agreed to sacrifice Suraj's future for the family's sake. This sacrifice might've been the right thing to do at the time, but a mother doesn't see right and wrong when it comes to her child; she only sees her child! It's true that she eventually found out about the lie, but it was too late by then. Also, she must've been more able to see that Suraj had taken the right step, as it helped the family avoid an even bigger crisis.
We also learned from Babasa's speech that Suraj has a history of doing what is necessary to avoid Bhabho's love for her son from overtaking the family's interests. Bhabho's love wouldn't have allowed Suraj to gamble his money on Vikram's shop, even thought it was in the family's interest. Bhabho's love wouldn't have allowed Suraj to waste his hard earned money on loser Mohit, even though it was in the family's interests. And it was her love for Suraj that allowed for Chavi's marriage to be approved. This also explains Suraj's decision to hide night college truth from Bhabho. He must've thought that this was in the best interests of the family, but Bhabho's love for him would not permit it to happen. And like always, Bhabho will understand when the truth eventually comes out, by seeing the positive results. (IMO, the ideal time for revealing the truth would've been when Sandhya successfully learns to manage both house and studies; but I guess this wouldn't have been ideal for TRPs.)
Anyways, let me end here. I think you're being a bit harsh with your lovely Bhabho.
But I can understand your position. Bhabho has to eventually understand to put more trust in Suraj, and not suffocate him with her love. Let's see if she goes in this direction