I am currently trying to build a wall around my settlement, and I would really love it if I could connect an entire wall instead of placing them piece by piece with gaps between them. Problem is whenever I try to snap a wall to another it will only let me do that at 0, 90, 180 degrees. I'm unable to find a way to fine-tune the direction you want the object to go if you snap it to another wall. Anyone got any tips for this?

Edit: Also, any way to actually rebuild walls etc on the houses you can't tear down? I want to live in my old house but that thing has more holes in it than a swiss cheese at the moment..