Re: Live drum mikes
rendezvous is right. Live and the studio are different beasts - in the studio you can use basically just overheads and a kick mic and get away with it if you have quality mics and good stuff in the signal chain, because you can minimise spill and use the overheads to pick up tone from the toms. If you have nice enough mics, tuning, room and placement then the only thing missing is usually some low-end from the kick. But in a live environment the whole setup is different - generally the cymbals will carry pretty well without microphones up to fairly large room sizes, but the toms vanish almost immediately and the bass drum loses bass pretty sharpish too. So you tend to see it as re-enforcement rather than trying to capture what's happening.
I've done engineering gigs with just a kick mic and tom mikes, both mixed pretty low. They work enough to fill out the bass and tone from the drums, while the snare and cymbals still have enough cut to make it through the mix. But ideally you want complete coverage.