Get some decent free piano, Take One (mda piano, 4front piano module, or perhaps some decent multisamples for directwave). About the guitar, you might want to get some guitar samples and an amp/cabinet/guitar fx sim (if I use a guitar, it's a free multisampled Strat with a Slayer 2 FX rig).

How about merging the stereo channels on the colonius lead's mixer track? that should eliminate the annoying autopan effect.

The fl drums are annoying to me. while after a bit of processing they may sound good (for my hats in my trance tracks I use just cb_hat and vt_ohihat2), they don't sound really good when they're dry, and some don't sound good at all (especially dnc_hat... *shudders*).

oh also, I don't know if the snare is supposed to be dark in jazz music (I don't really listen to jazz [/n0b]), but how about boosting some highs on the snare in the jj2 theme?