that whoole carapace idea is a very good Idea I agree to it.
from a marine side I love the shottie,
from a alien side I hate it, well not so much hate but more of an annoyance, it'd be hate if I played aliens more often.
I know it long hallways that using a shottie works just as well as your chances of actually hitting something is really high, and if they far away you can get a lot of shots off, I know the fact that they scatter and might miss helps ym aim (yes, I actually count on the fact that Ill miss because I knwo skulks movce faster then my reaction time
) I'd say to maybe lowe the damage of the shotgun a little, or lot which ever would be needed.
But ABS's carapace idea is a good one, im for it.
and as a totaly abstract MvM point of view of it, Shotgun pwns, but a good counter for it is the hmg.
(sorry, had to add that)