To respond to the USAIGC question, That runs basically from the winter (or early spring) thru nationals in June.
My dd being a Level 8 (this year and last) competes them both at the same time, since the seasons are pretty much the same. Last year she did level 7 (in the fall), then level 8 and USAIGC Gold level thru June....so last year was indeed all year long. This year will only be 1/2 the year. But, USAIGC typically scores higher, and its not as rigid as USAG, so its nice for the girls. Its a good ego boost, and builds some self-confidence. Some gyms compete just USAG, some gyms compete just USAIGC, and some both. Our gym does both (I'm in NJ). I don't know if all of the US does USAIGC or not. It seems like on this forum some people never heard of it, or perhaps its just that your gym chooses not to participate in it. Either way, its fine.
Hopefully that explained it a bit.
And, thanks for the kind words about my dd being 12 and a level 8. Its a tough level, and not one I think she is going to move out of that quickly.