For signing autographs, I always write either CC-7738 Commander Bacara or just CT-7738 depending on the costume I am in at the time. Most people just do what works for their own persona - although I'm not sure anyone uses their real name.
As for the parade speeder bike, I know that Judge_Hellfast from the 70th Explorers Garrison has a working speeder bike that they are able to use - not sure how much use it gets in parades and such, but it looks (to quote Peter Griffin) freakin' sweet.
Personally, while I think the speeder bike is a good idea, I'd work on the armor first - and Martin is right, get yourself a legion approved costume. If you like the camo look, perhaps a 41st Elite Jungle Trooper?
-Kyle