In that film, when he was kid, he was very poor, servant child, his mother worked as a maid for a rich family. Now rich family, they had a daughter, the gal and this poor boy turned best friends, but on that girl s birthday party, I guess she puts a blame on him of robbery and he is send to jail and something happenes to his mother and in jail he is tortured like hell inspite of being innocent. So he returns to take revenge.
Arjun is also connected to his childhood, he dint dance with Sam, ignored her, it was small part of revenge. She had done the same with him. He might be like bazigar. He is come to take revenge with samrat.He must be wronged in a big way.
I think his relation with Sam is like in bazigar, SRK s with Shilpa s Shetty. To destroy samrat, first pawn is Sam. Neil getting angry in today s episode shows that Neil is her hero, her saviour. He was teasing her with new boss and now he don't like her giving attention to Arjun.
Rads story has taken back seat but anyways her story would be struggles at achieving her dreams, dealing with different people (those 2 are really annoying).