Originally Posted by
FBinNY
... might as tell you that riding the bike is bad for it.
It IS bad for it! lol. Wearing all these components out, replacing drivetrains, etc...
Kidding aside, FBinNY is right. The drivetrain can stand a lot, and cranks themselves can stand up to a lot and will not 'wear out'. They won't break either: I stand on the cranks/pedals on my kid's 16" bike all the time and they are fine.
The OP's problem sounds like chainring bolts.