How difficult is it to hang things? The bathroom in my Jayco has a mirror glued on the wall, no medicine cabinet! Thought about taking it down and replacing it but decided against messing up the wall. There is room to hang a cabinet above the toilet but I'm not all that confident about hanging things on flimsy walls.

Hanging things on interior walls is a little safer than exterior walls...you never want to accidentally push a long screw through to the exterior of the trailer (this has happened to more than one person). If your toilet wall is an interior wall it will have studs in it, and those should provide enough strength to mont a cabinet. Just don't get something too heavy, maybe order a cabinet made specifically for RVs (they're lighter).