I understand that this has gone quickly and the desire to drag your feet on the divorce - but two things to consider:
1) Being too obvious about dragging your feet makes it look like you're not detached - far better (usually) to drop the rope and at least LOOK like you're accepting it and moving on; the WAS is more likely to rethink things if they're no longer sure they've got you as their fallback Plan B option.
You can still do things to slow down the process if you want, but don't be too obvious about it.
2) You may get a better settlement out of him now, while he's anxious to move on and still has a little remorse, than later once he's locked into a battle mentality.
Also - right now he has no sense of what divorce will really be like. How about approaching him and saying "H, since we're getting divorced, I think it's time for a few changes. While you are still living here, I think we need to start implementing a schedule. Every other weekend you will have the kids and I will do my own thing. Also, you can do your own laundry from now on. "
Do talk to your lawyer first, as any precedent you set about custody and visitation may have implications in your divorce. Also, if you can;t trust him for a weekend with the kids, try an evening or two a week - will also give you a chance to see if he's incompetent to have unsupervised visitation.
