The biggest factor on how much crap they give you about mistakes seems to be in direct correlation with how much the agents like you (or dislike you). That has been my experience at least. They do tell people when they do something wrong, but that's really all those agents are there for. They were a lot harder on one shop owner I knew than they were with some others. One guy I knew didn't even have an audit until 4 years after he had his FFL.
The inspections are routine. Nothing really out of the ordinary.