Those women with whom nikaah is not permissible

Q: We have a situation where a family member has married a Christian woman. He claims that she is a proper Christian therefore he made nikaah with her. Is it permissible for a Muslim male to marry a Christian woman in today's time?

According to my understanding, today most Christians are only Christians by name. They are not the Ahle Kitaab or like the Christians of former times. They don't know anything about their Christianity religion nor do they take their religion seriously. They don't go to church nor read their bible. They have become fully westernized and have accepted all the theories of the scientists like evolution, Dawin's theory, the big bang, etc.

Based on the above, my question is, is it still permissible to marry their women in today's time?

Q: I have question a regarding marriage. I have been in a relationship with a girl for 10 years and she is Catholic and a very good human being. I love her dearly and have asked her to convert and she is not willing to. I feel very guilty for being with her for so long and having to leave her for religion issues. What is your suggestion regarding this matter? Can I still marry her? If so how should I approach it ?

Q: Can a Sunni (Hanafi) male make nikaah with a Shia Jafaria (Ayat Ullah Khumeni) female?

Q: Can a Muslim woman marry a non-Muslim? In what condition can it be allowed?

Q: It is permissible to marry one's step-brother's daughter?

Q: I am a Sunni Muslim girl and I got a marriage proposal from a Shia friend of mine. I wanted to know if I can marry him.

Some of the things I would like to mention about him is that his family doesn’t do shirk in a way that they don’t put anyone else at Allah’s place like most of the other Shia’s do.

Secondly, we’ll do the sunni nikaah and my Uncle is an Aalim so he will read our nikaah. They don’t curse or say anything bad to our beloved Hazrat Umar (radhiyallahu anhu), Hazrat Abu Bakar (radhiyallahu anhu) and Hazrat Usman Ghani (radhiyallahu anhu).

Kindly tell me if I can marry him and what conditions should there be if I haven’t mentioned them already here. 

Q: A girl is 16 years old and she got married to a 27 year old boy knowing that the boy was having an affair with her own aunty (girls mothers real sister). After one month of that girls marriage, her husband got married to her aunty. 

So my question is... is the first marriage halaal or haraam. If it is haraam then can the girl get married to another man without any divorce or khula?

Q: I really love my cousin and he love me too. We did everything together and I regret that but it’s happened now. He told his mother that he wants to get married to me. But his 2nd mother told him that she gave me milk and to him also. My mother never told me that even my father don’t know about this. Now we really love each other and we can’t leave each other. What to do?

Q: My father's sister suckled me once. Now I want to marry her daughter. I share milk with her elder brother. Her daughter is two years younger then me. Can I marry to her. We are madly in love with each other.

Q: My mother married a man aand they have a baby girl. After her husband died, my mother married my father then I was born.

Can I marry my half sister whose father is different and our mother is the same? We are both in love. If not, then what do we do?