Ah yes, thanks John. Of course, head hits aren't too likely with all that cover.
4. That's cool. The sense I get is that with the "vs. Group" rule, you're zooming out a bit and imagining the effects of a short battle.
Does this have a peculiar interaction with the 'area' and 'messy' weapon tags?
Autofire and spray seem simple enough - you just urge the shooter to use the +VOF or +1d mode of the tag. High rate of fire evens up force parity, effectively.
Area and messy, however, are expressly about hitting multiple people in the same timeframe/gear use that other weapons hit one. So when we zoom out, it seems we're obscuring a valuable effect of the weapon.
For single shot messy weapons (like grenades, or messy reload like bazookas) I'd be inclined to think the 'messy' tag has no effect: the messiness is the pretext that lets you fight a squad to begin with. (Slow or single-use weapons without an area effect of any kind, like a hurled rock, strike me as inappropriate for attacking a squad with, and the GM would have framed the move differently.)
Repeating messy or area weapons, though, seem to get short shrift. I'm thinking weapons like the incinerator (not merely autofire, but messy to boot), Flamethrower and HMG.
(I realize I'm bombarding you with mechanical nitpicking, this is just my thought process as I read the rules.)
What occurs to me is that for "vs Group" attacks, 'messy', 'area' are like a free VOF increase, while 'expend' and 'reload' are a VOF decrease (since they can't shoot as often).