You sound really good, like you're regaining your balance a bit.
The time with the kids is tricky. The obvious solution in a non-alcoholic situation would be for him to take them so he could spend time with them apart from you. Are you at all concerned about his not drinking if he were to show up at your house sober to take the kids out to dinner for a couple of hours? Can he exercise that much control?
If you feel it's necessary for him to spend time with the kids at your house, maybe you could put definite limits on the time he is there, from x p.m. to y p.m. Maybe have dinner late enough so he could tuck the kids in or something before leaving. I don't know--just throwing out an idea.