Due to walls being two tiles high, those bookcases would be literally through the roof. XD
Always something to loo out for. Also, I think you're using a table tile or ceiling tile for the floor (you can tell due to the edging). This can create issues with other tiles interacting. If you like that particular tile I recommend copy/pasting a middle version of it onto the A5 tileset and using it like that instead. (Set your selection rectangle to 16x16 and copy the middle pieces of the autotile). It'll get rid of the issues that can appear from using an autotile.
I prefer to think that the bookcases are crammed clear up to the ceiling. They needed to call in a team of carpenters to get them to fit.
The edging issues should be mostly fixed now, although there's one fiddly bit under one of the bookshelves which won't seem to go away.
I'd love to have a team member who could focus on the mapping for this game, since it's by far the most painstaking part of the game making process for me, but as long as I'm doing this solo, I'm trying to achieve the level of "not too crappy" with my mapping skills. The environments probably won't be consistently polished, but I'm trying to at least keep them interesting.