After that scene we also got Sid-Mom scene where he told her that he knew she made him sign those papers unknowingly and those were his papers of death or something like that.. he blamed his mom for that. When DD showed him the papers when he said all that i think he meant both the mothers. Anyway i don't remember what he said at that time i have to see it again to comment further on this topic.
And regarding the nani thing.. she wanted roshni to go to her husband's house since they got married. And Indian tradition ( in serials ) always say a married girl has to live where her husband is living...
Yash maybe a good person but he is blind. He can see Roshni has not gotten over Sid still he went on with the marriage. what kind of a guy is he that he can be manipulated by DD. Cant he think for himself?
And i agree the CVs have butchered most of the characters - mostly all the sidey characters.