I haven't read thru the entire thread, but just wanted to share my thoughts on the ?s you proposed.
1) I don't think Megha's love for Mohan is going to come as some epiphany to her after Amar's truth is out or she learns about Mohan saving Nanhi. I think the journey of Megha's loving Mohan started long back, and slowly, while helping Megha find Nanhi when she ran away, or saving Megha from Prateek, Mohan has slowly made a place for himself in Megha's heart. Megha has yet to allow herself to open up her heart completely though...and understandably so. As a widow, mother, and DIL, she can't afford to be "selfish"...I think she's justified where she stands. Its going to be a treat to see her allow herself to open up her heart and risk loving Mohan.
2) Mohan doesn't need to prove his love to Megha. She already knows how much he loves her. Thats why she had such a hard time believing that she would betray him. She even said it herself - "Tum mujhe itna bada dhoka kabhi nahi de sakte...tum toh mujhe..." In her heart she knows Mohan would never do anything to hurt her. She's just greif-struck at the moment because everything that's going on (or, that transpired before today's episode) pointed to the fact that Mohan sold the CD to DN. But I don't doubt that Megha knows how Mohan feels. He doesn't need to prove anything. I think Mohan knows this too...he knows that deep down Megha trusts him and thats why this has hurt her so much. I think it will just be a test of time...for them both. Megha needs time to mend her heart, and Mohan needs to step back and let her work her feelings out on her own...so I think he's right to want to be out of sight for a while - tho, in true Mohan style, he's going a bit over the top with it by leaving the mohalla all-together.
3) I think that by the time Megha allows herself to accept and reciprocate Mohan's love, the family will be on board...or at least I can dream. haha. All jokes aside though, I think the family will sooner or later come to accept Mohan. And with time, the way the the in-laws are, I think that they will see that Megha is their daughter and not DIL and that they are truly invested in her happiness and well-being. I think maybe Jiji bua will have a hand to play in getting the family on board, but I do have high hopes for the family understand that she has every right to fall in love again. (Am I being too ambitious? I know that this is all really far off, but this show is hatke, and I am hoping the typical saas-bahu cliche's will be avoided - as sonalji said in her RM interview).
4) Megha's FIL treats her like his own daughter. I think he understands her pain and plight just as well as any girl's dad would. And at the end of the day, a father just wants his daughter to be happy. I think FIL will come to know and understand Mohan in the coming episodes and so maybe the thought won't be so foreign and out of the blue. I do understand the pain of losing his son and how his DIL's remarriage will open a lot of wounds, but I think that Mr. Vyas is a loving, understanding father, and I think in the end, he'll come around.
5) I like Mohan just the way he is - Half Majnu (sometimes overtly majnu...) and half rough & tough crime reporter that has a good head on his shoulders and knows the ways of the world and how to roll with the punches (to a certain extent). Mohan is perfect (99.99999% of the time) just the way he is. We wouldn't love him like we do if he was anything other than who he is.
Just IMHO :)