User catching should not be considered cheese. Sometimes, your CPU receiver just refuses to break correcrtly on a ball, or if a pass is tipped, they let it just fall.
Rocket Catching has meant so many different things I have no idea what it means anymore... but back in the day, it used to mean when you bomb a pass to a receiver, take control of that receiver, and then hold the sprint button to get to the ball... it was glitched where the WR would always run faster than the CB when you take control, and it'd usually result in a deep TD.
Maybe it means something else now-a-days... I don't know anymore