My Fun Finders interior was really cheapened by that vinyl shelf paper back splash that came with the trailer so I replaced it with some nice embossed stick on Smart Tiles.
I heated the vinyl to remove it but made a big mess because the glue stayed on the wall. A job that should have taken 2- 3 hours ended up taking us 3 days to clean the glue residue.
Do your self a favour. If you have to peel it off, don't heat and the glue will come off with the vinyl. Better yet, leave it there and stick the tiles right over them.
We went full height but it's your choice. Make sure to read the instructions and lay them out before you start so you can plan for scraps and avoid repeating patterns. I didn't and it's not as perfect as it could have been.