Can he withdraw the judgment if I drop the request for support? Can he come after me again if I remarry?
I'm a bit unclear as to what you are asking. Once judgment is entered it cannot be withdrawn. The pending action cannot be dismissed unless both parties consent. But, I don't think that's what you are asking. Support orders can be modified before and after judgment has been entered when there is a change in circumstances warranting an increase or decrease in support. I don't understand the connection you are trying to make between withdrawing a judgment and a request for support.