Rights of servants

Q: What are the rights of our parents upon us as convert Muslims? (Mind you our parents are non Muslims) Since someone said, even their prayers don't help us with anything because they are not Muslims and they are therefore not important to us because they are non Muslims. Is this true? 

Another question is that once you get married and your parents ask you to do something for them whilst your husband refuses, who should you obey? We know Islam says jannah lies under your mother's feet so when it comes to that, which side does the woman take? Does she have to obey the husband and ignore the parents?

Q: I would appreciate your advice on how to take care of my parents.

Q: My parents are no more. During my mother’s lifetime, due to various reasons, I was sometimes harsh with her. I used to shout at her and speak rudely, and unfortunately I could not ask for her forgiveness while she was alive. 

However, during the final stage of her life, around two hours before her death, she became very ill and I took care of her sincerely. At that time, she gave me many duas. But throughout my life before that, I regret that I was often rude to her. 

Whenever I pray Salah, I constantly ask Allah for forgiveness for the way I behaved with my mother. Even after her death, I once saw her in a dream. In the dream, I was saying to her, “Please forgive me, Mom. If you do not forgive me, Allah may also not forgive me.” She did not say anything and was only looking at me. 

Please guide me on how I can seek forgiveness properly and how a person can know if Allah has forgiven them for such a sin.

Q: We are 4 children (2 daughters and 2 sons). My father passed away a few months ago. Who is responsible for taking care of and for the financial needs of my mother?

Q: What are the responsibilities of a daughter, who is an only child, towards her mother, who is a single parent? 

Do any of these responsibilities change upon the daughter getting married? 

What are the rights that her mother has over her?

Q: My son left the fold of Islam many years ago. We broke ties with him. Can I contact him now? Would I be sinful if I contact him since he is a murtad?