Your h's use of phone sex disturbs me. As well as the other stuff. That is really a completely separate issue from the A, don't you think? Has he always had an unhealthy attachment to sex, or is that a by-product of the A?
It sounds like the OW is a sick individual and is leading him down some disturbing roads, but...all the same, he's an adult and he's willingly going.
Regarding how to handle the startup, I would stay detached. I personally think you are beyond traditional piecing--you should really be working on how to set a firm boundary and stick with it. He currently has no respect for your marriage and so it is not the appealing entity that it should be. It is a freebie zone, where he can go to crash after he completes all of his other activities. I don't see him ever quitting OW until your home is a place of respect and boundaries. In a really weird, sick way, the fact that you are so 'understanding' of his A encourages him to keep it going, instead of having the opposite effect--H thinks of the loving devoted wife and cuts if off. Your kind behavior enables him to continue being a selfish bastard. I would continue to make arrangements for life on your own, detach a bit and let him truly see and feel what life without Deb is like. I know he is breaking your heart but you are strong enough to pull this off. Ellie has written many times that once the LBS finally has had enough and that..change...happens in their heart, their spouse realizes it immediately and changes their course of action.