Niharika ka raaz - Could be that she was NOT legally married to Mr. Amarnath, but just a mistress/gold digger. She had a family of her own and one of Nutz, Sid and Rishabh may NOT be Amarnath's children, but only Niharika's. That may be very well Ram's dear beloved choti.
It is too soon for a leap now... So, there would NOT be a leap.
About Separation - hmmm, I am on the fence. May be just to stir up the pot, the CV's will have separation, but I dont see a justification as of now. RaYa just not talking is NOT convincing enough for a separation.
Cheers, Jay.