Can I also get him to sign a contract waiving
his paternal rights if I agree to not make
him pay child support?
In some/many states that's potentially a criminal act. You're basically selling stuff there. Do NOT document that with a contract. And even if not criminal, it likely isn't an enforceable contract.
I want to make sure that he can't bother us
and be a negative force in our lives.
You don't have that power. He's either involved, or not, and it is HIS choice.
The best way to arrange this is to go through the courts and get all the appropriate orders. If he doesn't want visitation, the court may not order it. If the court orders support and you don't want him around, just refund the support back to him.
HOWEVER!!! Recognize that he can seek or assert visitation rights at any time, just like you could refuse to refund the support.
This isn't going to be a good situation for
my family or the child
You don't get to choose a "good situation" once you are pregnant. The rights and obligations are established by law and paternity. If he's a toad, the government can't make him into a prince.