Kitab

Bismihi ta'ala

There are difference of opinion among our esteemed jurists, so this is something you will need to specifically find out what the fatwa is of your Marja' Taqleed.

I would add that for us Muslims, compatibility is extremely important, not just in life ambitions, or personal preferences or feelings, but in lifestyle and ideology. For example, if you are a Muslim, you would like to have an Islamic environment in your household, and create a spiritual atmosphere, with correct divine direction, under Allah ta'ala. If  you are a follower of Ahlul Bayt (a.s.), you want your family members, and your children to live and breath the Imams as, and follow their lifestyle and represent them. 

This can only happen if there is synchronisation in belief and ideology as well.

With prayers for your sucess. 

Bismihi ta'ala

This question is similar to many other fiqhi questions, where one would need to refer to his/her Marja' taqleed. 

That being said, according to the view of most of our esteemed jurists, Ahlul Kitab are not najis, and as for temporary marriage with a Kitabiyah woman, most Maraji' also deem it as halal.

And Allah knows best.