I've finally got the Little Gem flying in a fairly repeatable manner - as has been suggested here, it really likes to fly right-right. I put a small wedge for right turn on the rudder, and ended up with a fairly long wedge under the right wing to keep that side up in the turn. What really turned the corner was adding some 2" x 5/16" extensions on the aft end of each side of the stab - this seems to have pretty much cured the pitch stability issues.
I took the Gem to WESTFAC and entered it in FAC Peanut Scale. I didn't get around to flying it until the last day of the contest, didn't really have a good feel for the motor I had in the model and didn't have a blast tube that would fit through the nose, so the best time I got was 40 seconds. It sure looked nice doing lazy floating right circles downwind, and I think with some power optimization it will be a competitive model.
The stab picked up a bit of a warp due to the temperature and humidity changes going from Texas to Arizona and back again. I flew the model yesterday as-is, but I think I'll make a new stab with increased span/area so I can get rid of the extensions and not have to worry about the warp coming back.
Video of yesterday's flights:
https://www.youtube.com/watch?v=SUIGMi6-FkY&feature=youtu.beMike