I think whatever is happening is good for Kunal. Values such as love, trust and relation which he was thinking about does not go so easiy. He will try to ignore them but it will always remain with him.
Kunal is a different character - unlike you and me. As Abhay keeps telling and yesterday even Raj mentioned - if some one talks to him nicely he gets offended and thinks other wise as if they are insulting him. Best is to keep challenging him and that is when he shows his true self. He does well when he is hurt. As all were mentioning Siddhi knows him best and she will be able to handle him well by always challenging him. If she is around (6 months) and he has to see her everyday that itself will to keep him on his toes.
As for Siddhi - even if Kunal keeps throwing crap at her, she knows that he loves her and will see his love in those craps. Anyways by now she must be used to those craps even though she is longing for his love. And also Kunal's love for her will stop him from being very harsh to her. She has bonded very well with the kids and she will continue to get their love and support which will keep her going. Good thing is Raj also acknowledged that Kunal is effected by Siddhi and will keep supporting her. I do not care about Veena and Gaurav, (becuase they never cared for Siddhi ever) but along the line I would want Seema to also understand Siddhi and give her whole hearted support as she used to earlier. If Siddhi sees Kunal getting back his self confidence and doing well that will keep her happy ( that is what she was thinking yesterday).
With the self confidence that he will now have, he becoming his real sel and with the ambition to make money (which he will make), he will be able to take care of Abhay and Richa's of the world. Siddhi will take care of the kids while he is busy with his professional career.
By the end of six months, I am sure Kunal will realise Siddhi's unconditional love for him, all MU's will get cleared and he will shower all his love on her (anyway he loves her but will not expressing it to her).
I do want to give any importance to Abhay & Richa. I always believe that one should do what is in one's own control and make oneself ready for the worst. What Abhay & Richa will plan and will do is not in either Kunal or Siddhi's control. So they should work on doing what is in their control and keep themselves ready to counter any bad ideas that the two nuts may have.