I wasn't super satisfied with the whole night king scene, but I think you could explain some of the apparent holes by the fact that (1) I think you're supposed to get the fact that the night king really just does not care that much about Jon Snow or any of the other mains, and (2) he could have been using them as bait the whole time. I'm not sure that makes total sense though.
I agree the most problematic part of last episode was how they got that thing past the wall. Best I can figure the rules don't apply if you fly over or around it.