Do you know if it still has the stock clutch installed? The stock clutch doesn't have spring on it, so it will always drag. Wheels turning when they're off the ground (and even creeping forward with them on the ground) is pretty normal for it. I'd replace it with something like the MIP 4-n-1 clutch. It has a spring to keep the clutch from engaging at idle, and performs better anyway. It's just about the best $11 you can put into your GT.

And no, the GT doesn't have reverse, up/forward trigger is just the brake. It's more motivation to keep from running in to things

Enjoy it [8D]