slide in camper questions

[TowPro]

I found an older slide in camper I may try to buy. Even though I have a 32' 5th wheel, its tough to hall it 4 hours just to ride my dirtbike and spend the night by myself.

This is a small camper, its not longer then the truck bed, but I think it has a bunk over the cab. It is not fiberglass.

What supports the weight of the camper when its installed, the floor of the bed of the truck or the side rails?

Because I have a bed liner and rails for my 5th wheel hitch, I may have to build some kind of frame to raise the camper a couple inches. but first I need to understand where the weight rides, to bring it home can I throw a couple 2X4's in the bed to keep the camper higher then the 5th wheel rails?

can I even have a bed liner with a slide in camper? (it's an under the rail type liner)

If the current owners don't have any of the truck mounts, what am I looking at spending to build/buy the thing to hold the camper into the bed? not looking at going off road with it (its a 2wd truck)

Can I use a strap made to hold a boat on a trailer just to get it home? (about 5 miles).

When the camper is up sitting on those poles (out of the truck) is it safe to go inside of it?

I know what to look for as far as problems when buying used RV's, but is there problems that only slide in campers have that I should look for? (like side mounts rotting out, etc)

I been camping all my life, but never owned a slide in camper!