Pretty awesome but if you haven't already, you may want to strengthen the fastening of the shelf to the rail mounted to the wall. Right now with the shelf upside down, that's the only thing keeping it from dropping, since the side braces no longer lend support. Even with more fasteners there, I wouldn't put a bunch of weight on it, as that connection is at the weakest part of the radius.
Regarding cleanup, it looks like there's some tape residue, I'd clean that off with some adhesive remover and a scraper and to fill the holes, you'd just use some spackle. You can get it in a squeeze tube, apply it over the holes and screws then once it's dry, wet a paper towel or wash cloth and wipe the putty smooth and flush with the wall.