Okay, with my nice collection and a couple mods/aftermarkets tossed in, I actually finally read all the rules (players & time slim hereabouts). Seems pretty straightforward; just one question right now:

if you get a Stress token, that doesn't keep you from attacking, right? Just taking an "action?"

Correct. Actions are a very distinct thing, and firing during the Combat Phase is not an action.

It also prevents you from executing a red maneuvers next turn.

The other exception I can think of is Tycho Celchu who can take actions while stressed.