Will this rust on gears be an issue?

You can't get the pits out with a wire wheel. I guess that 550 hp means you have a weak clutch pedal foot and can't control high rpm clutch dumps. Is that what that means ? The worst that can happen is it breaks. Some of the above guys may be luckier that others, but just because you get away with something not breaking is not much of a recommendation to me. You can't put the metal back. Just swap out the ring and pinion. Not really expensive and cheaper than breaking it.