Looking good.
Just a minor point, however:
tackling, kneeing, and all that jazz in the professional level should be added to the basics. My opinion, of course, but those things are foundation skills that
all gladiators should learn unless they want to get ... you know, killed
It doesn't make sense that TEN brightening's worth of training wouldn't cover more than just kicks, punches, neck strengthening, and groin / body blocks.
I suggest adding some advanced basics to the professional level such as throws, counterattacks, and even grappling. Horns would be emphasized too, I think, as well as fighting off more than one opponent or emphasis on taking advantage of weakness by charging. Minor disarms should be mentioned too.
And I know that Cool moves are tempting at higher levels, but I suggest allowing some creative room for PCs that will pursue this type of Zinn'ka.
Instead, focus on separate functions of the form. In elite level, for instance, the practicioner will learn how to use advanced disarm, or even disabling techniques. Think Ninjitsu. But badder and bigger!
Master level would fall somewhere between using the terrain to one's advantage. The walls, various obstacles, could all be used to one's advantage. I'm thinking super body slams, horn drills, and demolishing punches and kicks.
Grandmaster would be a whole new plain for the supposedly unarmed Minotaur. I like the ironhide concept. Definately something that needs tremendous amounts of conditioning up to this point. The key is to introduce 'techniques' not just moves that are suddenly powered-up. That's understood. A Grandmaster punching would be like the force of 100 beginners charging at once.