Cool paint job..Ive used gorilla tape before...like the hole under side. Worked pretty good and made it alot stronger. I was also thinking of trying some spray can bedliner, or plasti dip.
Nice job with the paint,what I use to protect the paint job is glue on spray like 3m and then some primer your paint job cold chip and it will stay in place,you have to give it a couple of coats of glue and primer.
I did drywall tape then coated it with truck bed liner, I had to do 4 coats so the drywall tape was covered a little bit. The stuff I bought took about a week to fully cure, but it works awesome so far, my body is just super scratched up and has two spots on the front where the nuts on the ends of the shock mount are hitting body.
Wash the inside of your body before you do anything do it, with some dish soap and water, then dry it out really good. I would start with 2 coats and see how it feels, it really depends on what bed liner you are using some will take more coats than others.