Eating from a Shia

Q: I work in an office as an accountant and there is a girl in the office who is a Shia. Sometimes she brings something from her house and gives all the staff to eat and she also eats herself. Some occassions she gives money to something to bring something for her to eat for herself and she also offers us (the staff) to eat.

So my question is, can a Muslim (Deobandi or Barailwi) eat when any Shia gives anything to eat whether cooked or brought from the shop (like chips, biscuits) etc. Is is permissible. I personally do not eat but other Muslims eat and she feels bad and says that I will not eat from Shias. Is it correct what I am doing?

Fulfilling the rights of people

Q: Despite being very careful and conscious with fellow humans that I don’t hurt anybody in anyway but still I feel guilt and look for instances in my past where I might have hurt somebody with my hand or tongue but there are always shortcomings intentional or unintentional.

My question is what if we did wrong to somebody in the past and don’t recall who it was or if it was minor or major. For example, abusing out of anger if someone hit your car what will be the punishment or how to repent to Allah Ta'ala as I read that Allah Ta'ala will not forgive such and such violations of huqooqul ibaad. These thoughts are disturbing me and it's becoming hard for me to be a productive Muslim because of these distressing thoughts that I will burn in hell whatever good I do.

Even though there were many examples where people did wrong to me but I didn't take any action rather let them go. I must have done bad deeds too but not too sure when and where. I feel distressed and hopeless trying to be so perfect where people don’t even bother much and they are still happier.

Moreover I start to fear death at times and what will happen after that etc and my mood is depressed a lot of times please suggest me what should I recite and hope for the mercy of Allah.

Breaking one's fast according to the sunset time mentioned on apps and websites

Q: I’m fasting. I try to follow the most accurate sunset times. Of course these different sites and apps make estimates of what sunset time is. For e.g, today one would said sunset is at 3:53, another two said 3:54 and another site said 3:55. I naturally would follow the latest one as a precaution, but nevertheless, would it be permissible to follow the earliest time?

Muslim woman inheriting a house from her non-Muslim mother

Q: A non-Muslim woman owns a house in a non-Muslim country. When she passes away, the law of the land gives the entire house as inheritance to her Muslim daughter, who is her only child. What should the Muslim daughter do with the house, given that a Muslim is not allowed to inherit from a non-Muslim in Islam? Should she give it to the state? Or should she give it to her non-Muslim aunts and uncles, even though these do not expect to get it? Or can she keep the house?