What does 'dissed' mean please?
Remarkable is the engine's ability to produce those high power figures on that crappy fuel. The Nakajima Homare engine had a higher BMEP than the Daimler Benz 605 so it's hardly surprising what it could do on race fuel.
The American test was conducted with a later model Ki-84 by the way, we have the Ko (Ki-84-Ia) Early Production. This is the poorest performing Hayate if you discount the emergency materials models.
I've never lost a wing part in a high g turn. The structure is very strong as the wing was integral with the central fuselage section. You should be wary of exceeding 450 m.p.h. however as control surfaces can randomly shed. If you are diving at those speeds though you really are missing the point of this aircraft.
The Spitfire Mark XVI in my experience slightly out turns (except at very low speeds), out climbs, out accelerates, out dives, out runs and has better energy retention than the Hayate. This is exasperated above 7k where the supercharger loses effectiveness. However you can't do donuts on the runway in a Spitfire.
Incidentally, the flaps are wrong in Aces High, someone should fix those.