Except for the marker light issue they sound like freezing or cold weather issues. Was it winterized correctly? Tube surround also may have broken due to severe cold this winter but it shouldn't have.
A motorhome is like a house on wheels so just like buying a new house you will likely find a number of issues.
I had a number of issues that I just fixed myself. Didn't need any expensive parts like you will so it wasn't worth the gas and time to get it back to the dealer. Things like mis-run water piping, improper anti-sail adjustment of the slide toppers, oil leaks on the Big Foot jacks, air conditioner duct blockage by trash, missing fuse in the engine to coach battery charge control circuit, severely mis-aligned hood, leaks in outside lights that caused bulb failures until I figured out it was a leakage problem, and various cosmetic or sloppy installation items. This forum is a great source of information to identify issues you may not yet know you have and find out how to fix them.