Wife wishing to serve her parents

Q: My question is that my son is married and is living in another town which is half way between us and his in laws. He wants to move back to where we are living but his wife's does not want to move as she feels that she has a duty to live near her parents as she is the oldest and has no brothers. In Islam, should she obey her husband as to where he wants to live and accept it or does she have any other rights? There is no restriction to her as she is free to meet her parents as she wishes.

Sarcasm

Q: Is being sarcastic correct according to the Sunnah and Quran? I mean sometimes sarcasm can hurt someone. Please explain in this case. 

Working as an interpreter

Q: I work as an interpreter in hospitals in Delhi. Foreigners come for treatment and the hospitals give me some percent of investigation that patients have done for treatment. I asked several people who have the responsibility for marketing about additional charges when a patient comes through an interpreter. They all answered that the fee is the same when they come directly. Is it halal for me or not, if not please explain halal ways of earning as an interpreter?

Method of conducting ta'leem

Q: We are 4-5 ladies having taleem weekly in a small town. We read from Fazail e amal and sunnah kitaab, questions and answers (those which we cannot answer, we answer the following week). Ladies want us to talk also about akhlaaq, death, etc. Kindly recommend kitaabs we can use and also provide correct format of having taleem and any other things we can discuss. Also duaa to be recited at ending of taleem.

Father ill-treating mother

Q: I'm female and married. Right now I'm passing through difficult times and this is between my parents. My father is not speaking to my mother and this happens every six months on such small things. I have 2 younger sisters. We never interrupted between them fearing that they might get separated.  He is not staying with them and threatening my mother that he can marry any women if he can.