Legal issues aside, I ditto the mechanical issues with water tank.
When I bought my Fleetwood camper, it did have some dryrot, but having aluminium frame made me confident about integrity. So I took the camper off with full tank in my driveway and couple hr later noticed the floor separated from front wall.
I repaired and reinforced the front wall (surprisingly there is no aluminium frame in this part) but now when I take the camper off, I always put horizontal 4x6 under front floor and block of wood to match the height.
In my camper the rear overhang is several inches lower than floor and than generator pipe stick under, so I have to set the bottom of the camper at least 16" above the ground.