STINGER Son your ego is writing checks your body can't cash.
Maverick's "ego" doesn't seem to care at all about rules and consequences. With a word like "body," Stinger clearly means "Maverick's career." The implication is this: he's trying to be as awesome as he can, but it will ultimately damage his career—or maybe even get him killed.
STINGER: You've been busted, lost your qualifications as section leader 3 times, put in HAC twice by me, with a history of high speed passes over 5 air control towers, and one admiral's daughter
Wow, Maverick has done all this, and he's still in the Navy? He must be one hell of a pilot. Stinger's summary of Maverick's discipline record makes it clear: this guy does whatever he wants, and he can't seem to follow the rules for very long.
VIPER: You took it, and broke a major rule of engagement. Then you broke another one with that circus stunt fly-by. The rules of Top Gun exist for your safety and that of your crew. They are not flexible nor am I.
This is the second time Maverick has been yelled at in the film. While maybe Maverick's rule breaking has some purpose (to save Cougar, to get some points towards the Top Gun trophy), it endangers the entire team. Iceman will call Maverick out on this several times in the movie. Not cool, Mav.
JESTER: His fitness report says it all. He's a wild card. Flies by the seat of his pants. Completely unpredictable.
Instead of something like "flies by the rules," or "textbook perfect," Maverick's "fitness report" points to his volatility, and the fact that you never know what rule he's going to break next. He's "unpredictable."
HOLLYWOOD: Don't you leave me, Maverick.
Hollywood knows the rules. Goose does, too, and he reminds Maverick not to leave his wingman. Hollywood and Goose keep reminding Maverick of the unofficial rules of dogfighting, but Maverick is too hotheaded and can't resist going after Viper.
JESTER: You never, never leave your wingman.
Jester reiterates what Hollywood and Goose told Maverick during the previous hop. This has been a recurring problem for Maverick, and this is really the first time he's criticized for leaving his wingman by a superior officer. Busted.
MAVERICK: I'm not leaving my wingman.
Maverick goes from a big time rule breaker to a big rule follower by the end of the film. Merlin keeps telling him to get out of there (it's really hot), but Maverick will not leave his wingman, Iceman, because if he's learned one thing from Top Gun, it's that you never leave your wingman, no matter what.