We are forgetting one thing. FB is not yet fully told to us. Durga/Nithya has more or less seen all of the artillery of enemies. She was ambushed to say least in her quest for justice. She lost everything.
Yes she is thriving on their ignorance, just like Nithya went for Payal during trial. It was Nithya's ignorance on the power structure and her social status that went in favour of Goenka's.
Nithya was attacked from all sides. Even people who she trusted will stand by her went against her like Dev, Payal's friend etc etc..
She more or less knows her enemy. Their weak points, whereas Sakshi suspects, but unless and until Sakshi knows she is Nithya her real tactics is difficult to guess. Sakshi understands Durga wants to trap Shaurya. Wants to be a Goenka Bahu. But she hasn't yet reached why.
Sakshi would have won Bagchi if not for Aakash the mole. Sakshi's problem is she is playing without knowing the real enemy, just like Nithya in part 1.
Coming to marriage if they are going by Revenge, marriage is a sure shot possibility as in that Emily marries Danielle Grayson Victoria's son. Only diff here is there Victoria was the target, here Shaurya is the target. . Ideally as per Revenge Durga should be marrying Shaurya.
But there Danielle was not a rapist and he was the eldest of Grayson family. Where in EHT we have Dev.