thanks for recording footage! I did indeed watch all of it and was able to fix a bug where the AI froze up thanks to you.
To answer your confusion about the guns turning over time, that behavior is indeed a feature and not a bug. The idea is you're meant to "swing" your weapon using the mouse cursor instead of hovering it over your target. Alternatively you can aim your weapon before entering an encounter so you don't have to wait for it to spin around. Guns are all procedurally generated and rotation difficulty is one of the stats they're created with.
I get this feels really weird and unintuitive but it's a unique spin on top down shooting I wanted to experiment with.