OK, sleeves up time again...
Black and white thinking here is the only way to go.
If you want decent, normal fathers for these children, you are going to have to re-marry... 
These men will NEVER be normal. Give up on that idea. You are wasting grey matter in wishing they were.
a1b2 - I'll agree with strewel, but not on the long winded legal stuff. Short sharp and to the point. NO negotiation. You tried it, it didn't work. Time to get THICK (as they say in Ireland) and dig your heels in.
TELL him that there will be NO holiday. Full stop.
When he can prove he has made suitable arrangements both for transport and address ONLY then you will discuss the issue, but until that time has come, you will suspend ALL visits. He is of course welcome to take you to court.
There is no lose position for you here. You get an address, you can get him for CSA, you get him to sort the camper/insurance etc out then your kids will be safe and you will get a break.
I wanted to get myself a Land Rover Defender (the jeepy one) but the rear seats are side facing, kids under 12/with a booster are NOT allowed to use the seats under any circumstances. They would not be protected at all in the event of a smash. My son would only ever be allowed to use the front seat, until he's 12. He of course would kill to use the side facing back seats, due to the novelty factor, but I checked this out, you can't put small kids in these situations.