The civilian enemies are just regular enemies as far as the game is concerned. Do note that mutants play the role of actual civilians (on terror missions for example). The armed enemy civilians are just defined as an enemy with a negative kill/capture score in the ruleset. And yes, they do trigger reaction fire , unfortunately. But it all depends on the circumstances - for a fresh gal with a flintlock a tough guy with a niner can be deadly opposition, warranting a reaction shot.
Stun damage can still kill
Stun damage (it's called DAZE in the new version) itself never kills, but all weapons that are not stun-dedicated (stun baton, cattle prod, zapper etc.) deal part of their damage (usually 5-20%, depending on weapon - some go as high as 50%or more lethal.) as direct health damage. Same goes the other way - most weapons that deal health damage also deal a bit of stun.
I wanted to ask - does weather affect only your gals, or enemies as well?