USASF doesnt make rules for all companies. Your most likely going to be able to cross compete at USA, GSSA, NCA w/e but you cant cross compete at worlds. There most likely will be some level 6 senior teams next year, not many but some out there if you go to the right event.
Some of the WORST teams I saw last year were two level 6 teams. I don't remember who they were but they were older ages, in college maybe, and had the worst tumbling and stunting I had ever seen. Just cause you are allowed to do something doesn't mean that it's OK to do. It was scary actually. We just kinda sat there and watched in amazement. Yikes!
Well sure, but there's terrible teams in every level that don't really belong there. Like the teams with one full and one kick-double that think they should be level 5, but then can't put up solid libs.