In North Carolina there is no way to voluntarily terminate your parental rights to a child. The mother would have to file a petition to terminate...

Would the mother get custody while living with another family and living in their garage?

I would need to know a lot more facts before answering the question. However, the ability of each party to provide a stable home for the children...

How long my child support be effected if I decide to be a stay at home mom?

If you quit, your child support would theoretically go up. However, a judge may impute your income from your job leaving it the same.

What can I do to protect myself?

You probably need to file a motion to decrease child support immediately based upon a change of circumstances.

You need to file for custody, the sooner the better. The longer you allow him to keep the child from you the harder it will be to get the child...

What happens when the plaintiff who won an ex parte child custody order lets the defendant visit and keep the children?

It does not nullify the ex-parte order, but it will clearly be relevant at the next hearing. If the Plaintiff is allowing you to keep the children...