I would define a shooting stance as an OCV bonus or, better yet, a means of negating recoil penalties.
To go back to the END question--I kind of have a problem with modern firearms costing END at all. Especially on autofire. I'm not at risk of passing out if I run a few mags through an assault rifle at full auto. The STR Min in these cases would have more to do with accuracy and with reset time after each shot. I'd seriously buy these down to 0 END if they aren't already.