1. When I move a shell on top of an other, it bumps off, how to fix this? I tried looking it up but couldnt find anything with the terms I used :/

2. I am trying to move and sew edges, (worked fine all day) but now I am getting to this specific part, and when I try to select the edges and use the move and sew command, it won't do anything, why is this? Its the same object.

EDIT on 2.: DÓh! For some reason the edges were cut, so Im going to merge and try again