I do live sound for 3 venues, one 200 cap and 2 400 cap at the moment and do FOH for Heidevolk (pagan metal), Deadcell (industrial metal) and Earth Crisis (metalcore), 3 totally different bands and I've seen quite a few venues worldwide, from 100 cap to 60000 cap.
Earth Crisis introduced me to the AKG D5 vocal mic. They brought one on a tour I did and I was really impressed. The mic really cuts through very well and is resistant to feedback better than a 58. It is a little aggressive around 2kHz but apart from that really easy to work with. I bought a bunch of them after that tour and never regret it!
Anyway: the most important thing is to get the backline balanced on stage so that everybody can hear themselves and doesn't annoy others (including the tech!). Work out your stage setup well so that you're not depending too much on monitors or even FOH sound to sound balanced. Also take a look at how your stage setup and volume effects bleed on vocal mics or other instrument mics (if you have your guitar amp volume really low on stage you don't want it right beside the drumkit, if you have a singer with a quiet voice you don't want the vocal mic right in front of the drum kit or the bass amp). In smaller venues all you need to worry about is getting the vocals on top and get some kick (perhaps snare and toms) in the PA to make it appear a little bigger. You don't HAVE to put shit on.