Having met the Sucksenas he became aware of the flaws in his family and hence the comparisons on so many occassions. He assessed Komal's behaviour, Aadarsh's nature and the Thakurs lifestyle and was quick to conclude that marrying Aadarsh is the best thing that cld ever happen to her.
He appreciates the positive things in the Sucksena family like them being literate, decent etc unlike them who can hardly see any good in him.
He is so innocent and to certain extent that he is slowly changing since he has fallen in love I guess that is why every one in family is irked by that. Isn't it taht exactly SS said 'Usse Ladki Ke Khatir Usne Is Ghar Main Sab Se Dushmaniye Le Li Hai'. So all his talk abt him not changing for anyone is null and viod it was just to pamper his ego.
Merarai well said knowing abt Kesars Preg was not his job he is not her husband. He is not an 'anteryami' to know that his Bhabi is pregnant by just looking at her. Lets no forget he is her BIL and most Indian rural soceities women tend to limit their interaction with the other men of the house.
Yes, if speaking literally he is not a mission but figuratively speaking he is on a mission with his so called biwi to change his family