I am more afraid at this point of dumping a new bike than failing the test. I figure if I fail I can retake the test , but if I drop the bike I need new paint and possibly bodywork.
Remember, you'll be going very slow, so if you have to, you'll likely be able to catch yourself, what does that bike way, 450 LBS or so?. Might want to get an engine guard though. Some will wrap the bottom of the engine guard with fire hose, or hunks of an old tire, and hose clamps while practicing, then if you go down at low speed , nothing should get damaged.
Not sure if they do it in GA. but up here there are private testing companies that have small bikes like 125cc dirt bikes, some even have mopeds, for an extra $20 you can rent theirs for the test. Might be worth calling around for. I'd definately STRONGLY recommend the BRC, the test for that course is much harder than the Mi. test, and they prepare you well for their test.
The U-Turns and such are no big deal, you can, albeit not cool looking, always make a Y turn, I'm more concerned with you being able to avoid an obstical, or and accident then looking smooth.