He is behind of support, in and out of jail, hasn't asked to see her in 2 years. Is there anyway I could just get him to sign off so someone else could step in as father?

Also, he has been arrested for several domestic violence situations that involve my daughter. I also suspect possible child molestation but it would have happened a few years ago so I don't know if there is no way to prove it happened.

You can take him to court.

If you have someone ready to adopt, then you may be able to get his rights terminated. Until then, if he isn't trying to see her, then there is no point.

If you have gotten remarried and have been so for one year ( requirement in many states but not all) then you can file for the adoption. Included in the adoption will be him signing his rights over for the adoption.