I was just gonna post some other suggestions..but everyone else has pretty much covered it. I do have a few though. The thing I thought could improve the most is the clarity, everything seems muffled to me, I'm not sure how you can correct that...I'd have to come visit you and see what your room looks like, etc..I do have some suggestions though.
#1: Mics: If that all you have heres what I would do (and remeber this is just what I would do). on Drums I would put the rode out in front anywhere from 2 to 6 feet, just off the kick drum, to capture "the kit"..behind the drummers right hand side I would put the sm-57, to capture the snare toms and some cymbals..play with these mic positions and I think you mau like what you hear.
#2: I may be wrong here, but that sounds like a bad solid state guitar amp, I think if you back of the distortion just a bit, put a little more mids in there, you'll get a beefy guitar tone. But in my little world, I hate solid state amps..tube amps are much much better..if you can rent one, I would...as far as micing goes, I would stereo mic. using the 57 up close and the rode anywhere from up close to a few feet back, whichever sounds the best..and definetly double or even triple track those heavy guitars.
#3: The guy has a good voice..I would just wet it a little.
#4: when recording digital, you wanna get as hot (close to 0db) without going over!! digital distortion is bad

, so as to take advantage of the S/N ratio..
ametth