This gets complex, very quickly. You need a good lawyer.
No.
wife
file for custody see links below
That depends on why he did not have custody in the first place, as well as where he is located.
I believe that Leland and his ex-wife Maui share custody of their kids
No. His wife Priya Narang had Primary custody of their daughter.
He has every right to go back to court to petition for joint custody, yes.
Children are not property and as such are not inherited. If there are family members that want custody, they can petition the court. The court will, with the recommendation of the appropriate agencies, grant custody to the appropriate parties, or put them in foster care.
Eminem has custody of his daughter and also his niece- his ex-wife's sister's daughter.
Sex between husband and wife play no part what so ever in a custody case. You must not that until a verdict comes out they are husband and wife legally.
If you live in the US and if the court determines that it's in the child's best interest for you to have custody, yes. The fact that the wife is illegal will not be a consideration at all.
Yes, if she has sole legal custody. Not necessarily, if you have joint legal custody. Definitely not, if you have sole legal custody.