Child custody & Family violent Court : ( Judge )

I am just asking if anyone have experienced anything like this, and been through it and knows what would happen, or know similar things hat can happen and been said by a judge at the court.

I have never been to court regarding to this matter, just wanted advice on it.

I am just asking for advice on Child custody & Family violent Court. Regarding to what does judges always say or do, when it comes to a father of the baby is violent and threatening to kill his unborn child and baby.

1 - Does the judge looks at the child’s best interest?

2 - Which parents is unfit to have full custody of the baby.

3 - Can the mother get and protection order against her ex-partner not coming near her and the baby.

4 - Does the mother has to wait until the baby is born to add the baby to the protection order against the father?