Ahahahahahaha at the “not assembled quite right.” Let’s just say that I did read the instructions aloud very carefully.this suggests to me that it's not assembled quite right. Or it might be uneven expansion from the insolation you talked about where you are? In any case, I would use your finger to push or pull the nubs into their slots, for structural integrity as well as other reasons. There are lots of posts on BYC about predators getting into enclosures that their owners thought were secure.

I think that “operator error” is probably the case. It is interesting, though, since it’s on a very stable platform.
If you think about it, the door side is probably not as strong as the back and (I’d guess) isn’t as effective as the back at maintaining alignment, so there’s less resistance to torquing.
I do (this is the swearing part) generally align the nubs. It’s just a function, I guess, of there not being an independent frame among which all this hangs. After reading the wails of despair about traditional right-angle wooden coops, I’m still happy with our purchase. We will probably buy another one (a medium) when we expand the flock.