#1
i want to use a tubescreamer as a gain/mid boost ala killswitch engage and shadows fall. will it work that way with a solid-state amp?
#2
of course it will work, but it won't sound as good as it would with a tube amp.
decent, but nothing better than decent.
#3
I think something like a proper distortion pedal would be better. Tubescreamer will only give you that top end for there famous pinch harmonics.

TBH Drop C with decent amp will get you pretty close. Apparently they used Framus Dragons in Rose OF Sharyn.