Did it say "as-is" on the contract? If it did sadly you have no recourse.
IMHO since so many of the appliance type items leak and do not work I would go first back to the dealership with a 'printed' list of all the damages and broken water lines.
Then if you don't get any action from them take that printed list to your local chamber of commerce and file the report with them and whoever issued the license for that used car lot in your town.
Regarding the delam. Just leave it, it doesn't affect the use of the RV. I had mine delam from roof leak. Fixed roof leak and after sitting in the sun a few days the delam went back flat.
Regarding the toilet, water pump, and heater all leaking? Sounds like the previous owner did not winterize the RV and all of them froze and/or all the water lines leading to them froze from water left in the lines during freezing temps.
IMHO because of all the above broken items, I would take that camper right back to that dealership and ask for your money back. Making sure you tell them of your intentions of reporting him for lying to you.
That is an awful lot of work and money to have to spend on your first RV. Give it a try to get them to take it back.
