No you don't have to wait here while the divorce is pending, but one of you have to be present for the final divorce hearing on that 90th day (or some day thereafter if you wish to schedule it later, the minimum is 90 days)
but you have children and he could object to you moving with the children out of state during the pendency of the divorce, the court will restrict your move if he petitions for it. child support is irrevelant to the parenting plan for the
vast majority of purposes. if he does not care you can go, and have him appear to finalize the case. but remember he has to know how to do this and be willing to sort thorugh the details or use your paperwork. so the
basic answer to your question is you can move if he does not object. also, technically you are supposed to give him a "Notice of Intended Relocation"
Seattle Divorce and Custody Attorney, Washington Divorce Law)