Asking a kaafir to make dua

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? 

Woman wearing short or tight clothing at home

Q: Sometimes I wear slightly short or tight clothing at home, e.g.: 3/4 pants or a t-shirt who's length isn't completely over my buttocks. However my aw0ah is always covered. I don't even wear sleeveless. However, my father says that this is wrong and disrespectful because we live with my brother and grandfather. He always makes me change. Please advise if this is wrong or disrespectful and if I'm allowed to dress like this in my own home. Outside I wear hijab

Hurmat-e-musaaharah

Q: I have some questions about hurmat musaharah.

1. Is it established between a mother and daughter?

2. Is it established if one has wet dreams about incest or a sexual dream that has mahrams?

3. Is hurmat cancelled if parents remarry and sincere repentance is made? 

4. Lust is a strong sexual desire. If I don't feel a strong desire but I feel some type of lustful feeling that I try my best to control inside my heart at the time of touching, is this hurmat musaharah?