Dirty, sweaty, and tiring is what I call this process! However I'm extremely glad we went the whole 9 yards and removed floors, wall panels, and ceiling panels. We are planning on having our Skoolie for a very long time and making tons of amazing memories...starting fresh is well worth the time invested to ensure we don't have mold growing under our feet or around us as we enjoy the world. The insulation in the walls was all fine, same with the ceiling, but the wood layer of flooring was almost all wet and moldy.
Regarding the process, I used both a hammer drill and grinder for removing the rivets to pull the wall and ceiling panels. The hammer drill worked great on the wall panels which had smaller rivets; easier, cleaner, and a bit faster than grinding. However the ceiling rivets didn't work well at all for a drill bit as they were bigger and differently shaped. There was a center portion portruding out that made it extremely challenging to keep the bit steady/straight. Used the grinder to remove all the rivet heads and pull the panels down on the ceiling.
Then swept it all out, used wire brush attachments for the grinder and drill to remove loose rust, and used a scraper to remove any rubber or sealant left over to have all floor surfaces ready to prime.