Nikaah & Marriage Issues

Women attending a nikaah in the musjid

Q: My brother is having his nikaaah at a masjid in December. He is insistent that his future wife would like all the women to attend the nikaaah at the masjid. He says that there will be separate facilities and the women will be wearing masks as a hijaab. He wants hadith or a valid reason as to why women should not attend. He also says if Nabi (sallallahi alayhi wasallam) didn't forbid it then why are certain Ulama say its not permissible while other Ulama say it is correct to attent provided there is separation. He argues that my mother should attend and keep family ties.

Could Moulana please inform me from the hadith and teachings of our Nabi what would be the correct thing to do.

He says that he will not set foot in his mother's home if she refuses to attend his function at the masjid. 

The rights of spouses

Q: Is this right that that husbands have no right to demand their wives to carry out household chores, including cooking, cleaning, or any other domestic work?

Is this right that a mother has no obligation to nurse or breastfeed her baby? Can she demand payment to breastfeed their own child from his father?

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?

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.