I disagree, to a point. While I agree that the C-17 isn't a fighter, and shouldn't be flown like one, I disagree that its capabilities shouldn't be demonstrated. Note I said the capabilities of the C-17, not how the C-17 can be flown in a manner similar to much smaller aircraft with a different mission. This means short field ops, tactical arrivals, etc, staying well within the -1 and 11-2C-17v3 operating limitations.
Remember, airshows are not for us, they're for the owners of the airplanes (US taxpayers). I see it as a way to show them that they're getting their money's worth on at least SOMETHING that is being bought with their hard earned money. With that in mind, airshow profiles (same as flyovers, that was beaten to death in another thread) should be flown to impress NON-PILOTS. You'll never impress a pilot, simply make him think he can fly it better than you. Fly the profile, be boring to every pilot there, and the other 99.69% of people in attendance will love it. Survive the routine, maintain your aeronautical rating, full stop, shut down, and shag the demo girls, cheerleaders, or any other target of opportunity.