#1
Yeah, ive been through quite a few guitars with floyd roses, and they all seem to have different sustainer blocks, and i know there is like a bigass one that is supposed to be a big upgrade. obviously, its name, sustainer block, means it adds more sustain. does it add any other benefits? Wouldnt it limit your push/pull radius on the floyd rose?
#2
Yes it will limit it, if you have a real Floyd Rose (most people mistake all floating bridges for floyd roses)

Anyway, if it was a serious tremolo, you wouldn't be needing sustain blocks. Only junk guitars need them. :/