reflectix, the bubble wrap stuff probably would not have any cooling effect, it does not let air flow through itself. It would keep the ceiling cooler though.
The eternabond tape came off 99%. Easy with a heat gun and a sharp scraper. There is some residue but it I leave it no biggie…
Yes, my camper is built like a boat hull, so I doubt standing water matters, but I rather it stay dry.
I took off this aluminum 14 inch plate (the white one taped on),

and then put in the AC, and put the plate on the front opening (to the left), after removing the Superfan (still have Superfan on the right of photo). I had an 8 inch exhaust fan, so put that in the aluminum plate now. This smaller fan allows just enough room now so i can put solar panels at the front, and no shade from the AC unit. Pics later when I install panels.
The solar panels are loose now, still wired in.