HOw about paring it down similar to stunt,,
Classic( or nostalgia) with no skill classes
Carrier ( basically anything goes with bonus for scale built up ala class one or two but an engine limit of say .46. this would be where skill classes would come in, say beginner, interm and expert. )
Profile class like stunt with two classes, expert and everyone else.
I KNOW its not how it was done, its not traditional,, but then traditional carrier went away during the floods,, oh I mean the epic much talked about rule change
Not absolutly sure how you would decide skill classes,, most likely on an honor system using peer pressure.
It works fairly well in stunt, there are a few here and there that linger in a class but usually they are "urged" to move up and do .