Shruthi, the things that you called out for which Adarsh stood up are exactly the ones I was referring to.
From where I see Adarsh, he is a mature man takes every step with a lot of thought to the impact that it will have on his family. He has seen Abhay's rash actions and the effect is has had on the family and he doesn't want to put his mother through the same ordeal.
As to what about his own feelings/love, with Swa not showing any interest in him, he knows that he can't really be with Swa because she is not interested and so will eventually have to marry someone - and that someone would never be able to hold the same place in his heart as Swa. So it doesn't matter whether it is Vanshika or someone else. And knowing him, he would accept it and learn to live with it without the kind of resentment and anger that Jaidev has towards Jaya. Adarsh, while younger to Jaidev, is more mature when it comes to relationships.
And while this may not exactly be the ideal situation for Vanshika, I can't help but say that she has brought it upon herself. She has been deluding herself for the past 11 years that Adarsh loves her! If she can assume idle chit-chat/friendly conversations as love, then there can't be much hope for her! Again, Adarsh being the kind of reserved person her is, I'm sure would never have said or done anything that would have egged her on.
P.S: I guess I got confused about Vanshika's name and assumed it to mean something else. My bad! But you have again come up with interesting symbolisms for it too. :)