Are you dubbing everything? I'm a little confused 'cause I don't know if you have two 57's, or if you're using the same one for guitar and the floor tom/ride. If ya have 2 of 'em it opens up your possibilities on the drums. For now, I'll assume that you're dubbing everything and only have one.
drums: If you can use all 4 tracks on
the MT120 for the drums, you might try mic'ing kick, snare, floor tom, and one overhead or kick, snare and 2 overheads. I'm guessing the D65 wouldn't be any worse than the realistic or fostex on drums. I have no clue what kinda SPL it can handle, so ya might wanna check that before close-mic'ing with it. The 57 might be better served on the snare or even the kick. I'd experiment to find the best mic combination for snare and kick and use the other two mics wherever. You may have already tried all this, what you're getting isn't bad at all for the setup. However you end up micing, panning things out a bit will probably help some. I'm usually pretty traditional here... with how you have things I'd pan the snare a smidge to the right and the tom off to the left a bit (as if the listener were facing the drum kit).
As for the bass, I'd definitely bring it up. Getting a good sound from the bass and the preamp is the ideal thing, but I know about working with what ya have. If you're mixing on the computer and have a decent compressor plug-in, you might be able to even it out some and add a little punch. Also, if you have an EQ plug-in, I suggest recording the bass "flat" into the computer (avoiding the less than stellar EQ on the 4-track as much as possible) and EQ with software when mixing. With EQ, sometimes cutting unwanted or overbearing frequencies helps more than boosting the desirable ones. Again, this is all on the assumption that you're dubbing to the PC when recording bass.
Just a few ideas to try out. I never know if something is going to sound good or not until I give it a shot.