Out of all the issues with this, I'm just here to post about the points and way it tumbles...
Right now, with 31 tumble, my character can do back flips, dive to the sides, but, only rolls forwards? How is it that somebody can do a back flip, but not a front flip? Depends on the person so it seems, but, it's more common to see somebody that can do front flips easier than back flips. So, should we add this in for character creation? "Do you do front flips or back flips easier"? lol
Yea...broken(not really, just, not well thought out)...back flip should definitely be the hardest one to do...lol