Thanks for the advice on drums. I've been playing around with some original compositions since I started this thread, and although they all sound more or less like garbage right now, I've figured out a couple of tricks with percussion. Like you mentioned, cymbals have proven to be pretty useful. I've also found the by pairing pulse kicks with noise kicks can free up a few ticks on the WAV channel, which is becoming more important to me as I learn how to manipulate synths to get some really cool sounds. Mostly my Noise channel just sits there with empty phrases haha.
You're right in guessing that I've already started playing with commands, and I've also started using tables for basic stuff like panning and envelope manipulation. Since you mentioned them, I've started throwing commands and whatnot in tables, and I'm getting some pretty cool sounds from them. So thanks for that bit of advice!
And you're definitely right about my some of the tunes being off by a tick or two. I recorded each channel separately before rendering the song in Ableton. Even though the waveforms are lined up, it seems like the gameboy's BPM fluctuates a bit. Seems like re-recording while synced with an ArdounoBoy with my DAW set as master helps a bit with the fluctuation, but sometimes the tracks still don't line up quite right. I'd record it all at once, but I wrote more parts than there are channels, so I can only record chunks at a time. Thinking I'm going to need to get a second flashcart if I want things to work right. Oh well