I agree with your approach. First of all, why does the WAS have all this power anyway to feel they can just walk right back in as easily as they walked out? Do they not realized the pain and damage that they have done? When my H moved out 5 mos. ago, the first three I would of let him back in a heartbeat because my "normal" world was turned upside down but the more time passes, the more I realize I don't ever want him back unless he is willing to change and "work" at the M. I'm at a point where I feel I may end up being D because H cannot communicate or address the issues...so sad because here he has a wife willing to love with all her heart and he going to possibly throw that away!
You deserve a H that is going to be the best H and father he possibly can. It may take awhile, but the first step is to acknowledge that he is willing to try.