Your truck is already overkill for that camper (which is great, you’ll hardly know it’s even on there).
Other than installing tie downs you don’t really need anything.
Rubber horse mats, cut into manageable pieces as mentioned will go a long way toward keeping it from moving around, provide a bit more clearance over your cab roof, and if you have 5th wheel rails in your truck bed they’ll level things up.
Isolating the truck batteries when parked camping is as simple as yanking the camper plug.
One little dummy-proofing mod I like to do is install a small LED on the front of the camper where I can see it, wired to the running light circuit in the camper.
That way I can tell while driving if I remembered to plug the light cord back in.