I am curious; what would be considered the minimum number of hours that an aircraft should be flown for piston engines, turbo props and jet, before corrosion becomes an potential issue?
Hval
Corrosion as such is probably not the issue unless the aircraft is parked outside near the sea.
Damp is a problem with sensitive avionics and other systems so an hourly number is probably not accurate.
You could fly your 100 hours in two months and park up for the remaining 10 months and still get problems so its more regulatory of use, is the aircraft parked outside? Is it in a dry hangar.
Aircraft do not like being parked up and not used and warmed through.
Regarding the different types Jets can be 30 to 40 years old! What stops them is not usually corrosion but engine life and maintenance bills on old systems and avionics or expensive new requirements.
When you consider a small jet engine has a life of 4800 hrs and costs $4-500,000 to rebuild the maths does not work out on old airframes and they really become scrap value.