I know my way around a piano, but really just improv (can't really read music). Most my experience is with mixing/mastering.
Ah, makes sense if you're mixing in-headphone, the EQ is so far from being flat. By all means, take my criticism with a grain of salt, because it sounds great already. It might be interesting to hear what a good mastering engineer has to say, to get that final extra polish.
This guy is well known and they have a simple web form you can use to get a 45-second clip mastered for free, just for kicks to see what they can do
http://www.hdqtrz.com/