Not really, that depends on whats the height you dropped your 580ex2, last few months i shot a pre wedding and my 580ex2 fall hard on a rock, resulting into cracks all around, cannot even fire anymore.

yeap yeap, its solid and great flash power output.

can i add on on the sharpness part?
not necessarily L lens then its sharp already, every lens is sharp also, if you stopped down to f8, every lens is sharp, definition of sharpness of lens is how sharp is it during wide open and corner to corner sharpness.