2 things that drive me crazy in RB:
--expanding the volume envelope under the track--too often i click somewhere on the track screen and I've inadventantly created a huge volume envelop when I didn't mean to...it's a good feature, but i would make the activation of it less responsive to random clicks in the track

--clicking on the chord window automatically copies and pastes a series of chords when all I wanted to do was to change the a/b part number...if I'm not watching real carefully, I've changed a bunch of chords when all I was doing was changing/removing the a/b part indicators..

Just some user feedback..