For the audio kit, would you consider adding some things including a few that are more geared toward notation for more coverage? I'm a former musician-now programmer (+1 coding kit btw) and could potentially get my own spouse into the custom keyboard world by making him a Sibelius-oriented setup
The things I had in mind for the moment are: an instrument of some kind (violin/guitar maybe), a clef (treble or bass), a time signature, a sharp, a flat, and a natural. Also somewhat subjective, but IMO a quarter rest would be more distinctive than the eighth rest. Most everything else that is notation-specific (slurs, key signatures, crescendos, trills, repeats, what have you) can be pretty well approximated with what's there already, which is great.