As others have mentioned, TGH apparently affects damage received by all attacks. Working in conjunction with DUR (total hit points), you can get some interesting wrestler builds in theory, which is what I've tried to do this go-around.
I'm still toying around with the REC attribute; the setup I've got is better than it was previously (I think it may have been your suggestion that smaller guys should have lower REC values, actually, which is generally the case now), but I'm not 100% sure if I'm "happy" with it yet. Part of the issue might be my approach, as I didn't come into this project with the idea I'm going to get gameplay that matches what I see on TV, as the game simply isn't built that way; it's a fighting game with wrestlers (albeit a very fun one) and not a wrestling game. Long story short, I'll give more dramatically decreased REC values a shot.
With respect to "edge values" for DUR - the thing I specifically wanted to avoid was having a bunch of people on the roster with 79, 89, or 99 DUR; my working idea was that if a wrestler is already that close to the threshold, just round up one point and award the extra 50 hit points. Since DUR is the only attribute which is so obviously discrete in its effect, it's the only attribute for which I apply any sort of rounding. I let momentum in Universe govern any other discrete changes caused by ratings fluctuations, which (with the exception of 90 or greater AGI allowing jumping to the top rope rather than climbing) are far less apparent to me. The "leveling up" effect you describe is exactly what I wanted to achieve with respect to Universe momentum, for the most part.
I do appreciate the feedback; again, I don't claim what I'm doing as a monolith by any means.