#2 is fixed for the next build.
Could you elaborate on #5?
6 is intended. Polearms take up two hand slots, so there's a tradeoff. Man-Eating Plants aren't intended to be very difficult anyways.
I'll be adding more variations of the Power Plant levels. I don't intend to make it shorter. 5 levels isn't too long in my eyes.
Axes, for the most part, have the same speed as swords. Larger ones can perform sweeping attacks too.
Weapon-specific skills are on my ToDo list.
Merchants are intended to be somewhat rare, and rare enough to make stockpiling gear not as easy.