Dealing with non-Muslims

Q: Is it permissible to give a translation of the Quraan to a non-Muslim who is interested in Islam, even though he cannot be assumed to be in the state of wudhu?

Q: At work with non-Muslims, my colleagues wanted to eat with me and I volunteered to buy the food. They asked me if it is ok if they get pepperoni pizza and I said it is fine. Later I asked them to just go ahead and order so I would not pay for their haraam food.

Since I first said “it was fine” is that kufr because I was too weak to explain to them that I don’t buy haraam food? I feel like I need to redo my Nikah and Hajj.

Q:

1. What is the ruling on a woman going to visit her non-Muslim maternal auntys house?

2. Are non-Muslim relatives automatically non-mahram?

3. How should a Muslim woman's conduct and behaviour be to one's non-Muslim relatives?

Q: I had a close non-Muslim friend. He helped me in all my difficult situations and helped me to grow in all possible ways. Now he is no more. How can I support him for his hereafter world? 

Q: Is it allowed for Muslims to live with non-Muslims in the same house?

Q: I want to know if a Muslim and Christian family can live together in one house?

Example: The Muslim family lives in one portion of the house and the Christian family lives in the other portion of the house. Is this allowed in Islam?

Q: My husband and I are disagreeing on something. So basically my husband has friends that are non-Muslim which I dont have a problem with. However my problem is that my husband and them pass their cigarettes around. In my opinion, I say it's wrong as they are non-Muslims and they drink and so on, so their saliva should not touch my husband's mouth. However, my husband feels that I am being unrealistic and it's not their saliva that's touching the cigarettes, it's only their lips. I still feel that's not right. Please advise what is the correct way for this.

Q: Can a person ask a kaafir to make dua without any belief that their idols would fulfil their wish. He believes that only Allah Ta'ala can fulfil the wish of the kaafir and that there is no other God that exists except Allah, but just saying "dua karna-pray for me/us" to a kaafir, would this constitute kufr which takes a person out of the fold of Islam? 

Q: Can I insult a kaafir if he insults Islam?

Q: I want to ask many people ask why we using non-Muslims' inventions practically and socially if we are against them?