Marrying a Christian woman

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?

Distributing an estate according to an unislamic will

Q: A lady passed away a few weeks ago and left behind a will which was not an Islamic will.

1. What will be the consequences to the deceased if her estate will be distributed according to the will she left behind?

2. Who would be responsible to ensure that the estate will be distributed Islamically? If the heirs decide to go ahead with the distribution according to the CURRENT will, what will be the consequences?

Purchaser demanding more money when cancelling the sale

Q: We had a sale agreement for our property five years ago with a person for 8 million rupees. He paid 2 million rupees in advance, and he promised that he will settle the balance of 6 million rupees after 6 months and complete the registration. However, he was unable to arrange the remaining amount of 6 million rupees. Now we are planning to sell the property to some other person. Therefore, I need to return the 2 million rupees to the person, but since it's been 5 years, he is now demanding more money instead of 2 million rupees. Do we need to pay the extra money?

Marrying an agnostic man

Q: I am a practising Muslim woman and I want to ask if I can marry a Muslim agnostic man. He lives by sunni school of thought, had a Muslim upbringing, is a Muslim on paper and doesn't indulge in anything haraam. He however, is struggling with the knowledge of Allah Ta'ala. He doesn't deny His existence but he says that he hasn't found a proof of Him as well. We both want to marry each other but I want to know if our nikaah will be valid or not?

Note: Agnosticism is different from Atheism and I hope that I made his beliefs clear.

Enjoying the pleasures of Jannah forever

Q: If Jannah has everything that we all desire, then we as humans may fulfil our desires and still not be satisfied. For example, having a sports car in this world will be nice but that excitement wears off. If Jannah has everything we desire, and we obtain it in Jannah, then what would be the excitement or greatness of such a place?

In other words, the good is only appreciated if there is also something bad or disappointing to compare it to. If there is only good, then what would we compare it to? 

Doing Istikharah to find out the truth

Q: Can I do istikharah for knowing the truth or is there any dua for revealing the truth?

Recently, I have been stuck into some confusions and doubts about my partner. But I really don't know if he is telling the truth or not. I saw many hints that's why I just cannot put trust on him. It's killing me inside. I cannot concentrate in my daily work. I don't know if it's true or shaytan is making me think things? So I badly want to know the truth so that I can stable my mind and move on. Is there any solution or any dua?