Airframe failures are very uncommon. Most always due to pilot error of the pilot flying the thing at the time. Big problems are flight into thunderstorms, and inadvertent flight into IMC -> spiral dive -> Vne. Also flying into the ground due to dumb manouvers at 50ft. I cannot see any evidence that the pilot before you stressing the airframe is much to worry about, I'd be more worried about me doing something stupid.
I wouldn't have the nerve to roll a C172. The roll rate is atrocious, expecially once you have rolled something a little sexier, and the sexy beasts aren't much more expensive to fly anyway. Some of them are even cheaper
