SchrodingersCat (love the name!), hubby did made the mistake early on of going right back to a full work schedule (which was 14-16 hours days for him at that time) and it did not end well, so he has been much better since. The worst damage from that period has been repaired for some time now, and we're working on patching over the remaining cracks. I think on my part that petty resentments do build up faster than they used to because of it, but we have discussed this many times and he's good about backing off when he realizes he's tromping on thin ice.
So, he is not the most hands-on dad in the world, but not useless either, and in between him, his sister, and the older nephew, I actually have quite a bit of help around the house. Even the two little ones pitch in. Younger nephew was a bit spoiled when he first moved in and we have been disabusing him of the notion that other people exist to serve him. :P
Anyway, though, I think you guys are talking me out of trying this, certainly for right now. I need to work on my insecurity more before I'd feel comfortable allowing anyone but a faceless one-night-stand in his life and my vague hope that some NRE (if I can find it) might help pick my sex drive back up is kind of hypocritical. Thank you so much for all your thoughts. You've really helped me think through the implications of this a lot more clearly.