I understand the frustrations. My kids have been going to bed 3-4 nights a week at least before H gets home from whatever he is doing (bowling, dinner w/co-workers, out for a beer, running hay, etc). I can't imagine he doesn't miss spending time with them like they miss him. So I totally get how you feel about D7 and your W.
I too still feel that my H should include me in his plans (not in the actual activities necessarily but tell me what he has planned) since we still live together. H told me he was going up to IA this afternoon for job paperwork and then to his parents' house for the evening. I returned a call from him a couple hours ago. He mentioned in the conversation that he was at a friend's house 100 miles from his parents' house? On a gut level I was aggravated b/c he listed his plans for me twice today and never mentioned going over there. He could have driven back home tonight and seen S and D. But instead he drove over to a buddy's and is spending the night in Iowa. Anway not to hijack your thread, just saying I agree, they seem to be focused intently on doing what they want, and we are more and more becoming afterthoughts. That is where I agree, the separation thing would force them to see how things would be different without us. Let me know if you figure out a way to separate without actually moving out