Bear,
When I play piccolo trumpet I always make sure I'm relaxed when I play. If you are tense when you play the horn will work against you. Also pics can have intonation problems. Basically the smaller the horn, the harder to tune, at least from my experience. A trick my trumpet teacher would have me do when I would get a new small horn, is go through the range of the horn with a tuner and play each note (don't look at the tuner yet) and play where the note feels in tune and centered then look at the tuner. Over time you will not only learn the tendencies are on the horn but you will hear and remember each note in tune. Just don't look at the tuner until you think it is centered, the key is learning how to hear the pitches.
Some other great Pic players to listen to are Guy Touveron and Eenard Soustrot (both students of Maurice Andre), Hakan Hardenberger and David Hickman among others have some sweet Pic sounds. Now we just need Manny to make a solo album............
