Will Pooja feel [be] forced to marry Shubha's son, to bring a smile back on Shubha's face?
I think Pooja will fall in love with Shubha's son's simplicity - I don't think she will feel forced to marry him but she will admire, respect & grow to love a simple human being with no dark shades in his character.
Will Pooja's problems with Karan and Vipul dying lead to Shubha and Pooja living together?
What might happen is that Pooja will walk out on Karan after pehaps more abuse from him & then Shubha will support her through that while in turn Pooja will move in with Shubha (as there is no room in Babli's home) & support Shubha through the loss of her husband. Both women lose their husbands but in different ways so they will understand each other sorrows.
Will Shubha be able to win Vasu back?
It is Vasu who needs to win Shubha back - she is rude, inconsiderate & a bully towards her mother - I have never seen her talk lovingly to her mom. I am hoping Vasu realizes her mistake when she loses her father - that she has only one parent left, Shubha & she needs to be nice to her.
Will Karan try to re-enter Pooja's life and be the "perfect" husband after their divorce?
I don't think so, I think he will just fade into the background.
How will Jassi have his revenge?
By making Geeti fall in love with him...that will be the ultimate punishment for Nanda which he wants - for her to lose her daughter to someone whom she knows is a good for nothing spoilt brat.