We noticed point 2/3 during testing as well, but it doesn't happen every time. I guess in a future update it would indeed be nice if the AI would try to maintain its supply lines (however, this could result in more conservative AI play and thus a bit worse AI play).
I'd disagree that the maps are too small, it's scaled in a certain way and that scale can only result in maps of this size so you could argue that the scale would need to be adjusted, but in this case I'd be against that as large parts of many scenarios would consist of no mans land that nobody cares about. Fall Blau is one of the operations that can be fairly accurately represented at this scale, due to the distances involved and the relative lack of participating combat units compared to offensive operations elsewhere.
Whether stacking is needed is a matter of preference, I'd say. I don't mind that you can't stack and it does mean that you have to do more planning for an attack than simply move a killer stack into position like you would in WitE.
I stand by my earlier statement that it's not a typical beer and pretzel game, but more of a mix of basic wargames with more serious ones, but you are naturally entitled to your own opinion.
WitE Alpha tester
Panzer Corps Beta tester
Unity of Command scenario designer