Like all other Balaji offerings, KAA is really working hard at keeping the audiences guessing as to whats going to happen next...
I actually didn't notice Nikhila's repitions about Shiv's khushi, or rather I assumed it had something to do with his life. I very honestly don't think that Shiv and Ipshita have a thing going. Except for that one scene where he's talking about Anupam to her, there was nothing pointing in that direction, besides the character sketches released at the start of the serial. If the second part is going to hurt his Dad, it probably has something to do with the land that is now Gauri's. Its life two birds with one stone- when Gauri dies, Shiv's kundali dosh gets cleared, and at the same time, the land is inherited by Shiv. Maybe the Kapoors are going through some sort of financial crunch and this everything rests on this project (for which the land was crucial). I guess thats the reason, Shiv gave Gauri credit for the project...
In the end, Shiv cares for his family more than anything, except maybe now Gauri (but then she's his wife now, thats family too)