I'm not sure exactly where all the wiring is in the trailer. Chances are good it's going to be low along the wall or near the corners to get up to the ceiling lights. For shelves you will likely be ok.
As far as mounting a TV in the bedroom, it's actually a very easy install to secure the mount to the wall. I added a 24" and drilled a 1" hole for the HDMI and cable to pass through. Using a HDMI splitter off of a blue ray player, we are able to watch movies in the main room or the bedroom.
Here's a link to the install and finding the backer board to attach the TV mount.
TV Mounting 101
2017 Forest River Surveyor 247BHDS...
...Tugged by a 2016 F250 XLT FX4 SuperCrew, Shortbed 6.2L, 4wd, 3.73...
...Joined with a Husky Centerline TS 800-1200lbs WDH