Maintaining good relations with two mother in laws

Q: I am 32 years old and I am married with 2 kids. My father in law and mother in law are divorced. After the divorce my  father in law remarried. His new wife was always kind and caring towards myself and my kids. Now that my father in laws wife and me get along, my own mother in law has an issue about it and she hates that my father in law's wife is a good person. She doesn't want myself and my kids to be good with her. I want to know if its wrong to be good with her or if its right to listen to my mother in law?

No longer want to be in a haraam relationship

Q: I am single with a 10 month old baby from a Pakistani. We live together but I don't want to get married because he is already married. I assisted him with his permit which allowed him to travel to Pakistan and he has now impregnated his wife. I asked him to leave as I no longer wish to be in a relationship and want to live my life as a pure Muslim woman. Is this wrong?

Entering a room without permission

Q: What is the ruling if the wife stays with her in laws in the same house, sharing all spaces like the kitchen, bathroom etc? Are the in laws allowed to use her bedroom as they wish? If she is not there can they sleep in the room and let other people in the room? The wife's possessions are still in the room and she is not informed of the people using it.

Written Talaaq

Q: A father of the husband while separated from his wife wrote a divorce letter which the husband signed and gave it to a third party.Some time later the husband decided to destroy the letter. Later on the husband and wife reunited. The wife had no knowledge of the letter and was informed of the letter only after she was reunited with her husband. Many years have passed by. Where does this marriage stand according to Quraan and Sunnah?