Totally fine. I used my matte black 7 Plus caseless and that phone is much, much harder to handle compared an an X. Play for the caseless team. It's far better over here. Alternatively, the Caudabe Lucid Clear case is the closest you can get to caseless while still having something.
That's fair. I did the same with my 7 plus, all the way back to the 4S and was always fine. I guess with the 4S I knew the back was cheap to fix and the phone overall was cheap to replace. I probably will go caseless soon, been itching to do it for a while now. I've been using an Apple Leather Case which has been nice, but the bulk and dust build up is a bit annoying.