Custody of children

Q: What is the ruling regarding divorced parents and the custody of children? Two prominent muftis have said that although the children are 7 and 9 years old, yet they do not go to the father as the father is not capable of caring for children. It will not be forced upon the mother to let go of the children and also the fact that this is not a muslim country so the mother will not be forced to. However, when the children reach puberty, then they are given the choice to choose where they want to go. Is this true?

Masturbation whilst Fasting

Q: 

  1. Does masturbation nullify the fast?

  2. If it does nullify the fast, does this person have to stay without eating and drinking for the rest of the day?

  3. When he takes ghusl, will he just rinse his mouth and nose or will he gargle his mouth properly and put water properly in his nose?