I am a silent reader, but this topic intrigued me, so thought i should reply.
To answer your question, I think it is Right, when you look at it from Kabir's point of view. Yes, he has erred, but that doesn't mean he can't rectify his mistake. In his defense, he didn't do anything "wrong" per say. Yes, he insulted Pia badly, but only because he is in love with her, and it hurt him to know not only that she was blaming danish, but also the fact that Danish told him "pia likes to play with rich men." And it's not like he insulted her in front of a million people, as far as i remember once it was in front of tracker, and the other time he was talking to Misha and he didn't know pia was eavesdropping.
In my opinion he should go ahead with whatever he is planning as long as he is sure of it.
As for the other people who think it's wrong, i have one question for you, if Kabir doesn't deserve pia, why does Abhay deserve her?(besides the obvious fact that he is the male lead?) At least Kabir only kept his emotions limited to his friend circle, but Abhay besides saving her ALSO insults her/man handles her(which is "sexy" but that's besides the point). Granted he is not human but the other "humans" don't know it, so why does he get the right to insult pia yet deserve to be with her?
P.S. I was/am/and always will be an Edward fan, and since Pyar ki yeh ek kahani is based on twilight, I will be completely on Abhay's side even if he does something evil. It was/is/will always be TEAM EDWARD for me, so for this show it'll always be TEAM ABHAY! (This post is just to show that Kabir isn't wrong either).