The more I think about this, the more I think he's really being a selfish ass if he's waiting for his wife to step up to the plate, initiate a divorce and deal with the elders. If she hasn't been really involved in 6 or 7 years, what would be her incentive now to stir up the trouble she will for herself by confessing her sins?
I think that if he really cared about ANYONE other than himself, his wife (after 20 years surely he still cares even if their love is compromised), his kids (why put them through more torture) or you, HE would step up to the plate and deal with HIS wrong doings. A good person steps up to accept the consequences of their own behavior. It's something I have instilled in my CHILDREN - you do the crime, you pay the price. Delaying that..well..I guess we all do that some of the time, but waiting for someone else to take the fall????? I think you get what I mean.
If he loved you, and had any regard for his wife and kids, he'd bite the bullet and confess to the elders, take the heat for being the "sinner" and live with the punishment. Yes it will be very hard on him, but he will have the opportunity to repent if it is important for him to stay with the org, or he can leave it without any rough edges. Right now he wants his wife to take the heat when there is little doubt he has committed a serious wrong himself.
What I am trying to say is that he is not being a man about this, and he is treating his family poorly. You will likely find him to be just as selfish and weak if you end up with him.
I remember my ex-husband's second ex-wife coming to me after a court hearing where he had just had her support reduced dramatically. She asked me how I could let him do that. I told her I didn't have anything to do with his choices, but why did she expect him to be any nicer to her than she'd seen him be to me? A rat usually is a rat for life.
I'm sorry to be so negative at a time when you want more hopeful options, however I think it is really important for you to try to see things as they are, not how you'd hope they will be. Then you can better position yourself to take care of you and your kids.