He's coming out of rehab and going straight home? What about going to a sober living facility?
To me: rehab to home without support = relapse.
It seems like you need time *away* from him, from his comments and manipulative suggestions, to figure out what YOU want. Is there anywhere else he could go when he comes out of rehab? You sound like you've got enough on your plate without having to deal with the impending relapse.
And NO, families don't *have* to stay together, especially when they've been damaged by someone's addiction. Sometimes, it's best for families to part ways, for the health and safety of most of its members.