Hopefully they abandoned the "dare devil" aspect mentioned in the casting sheet though.
McCoy is the opposite of a daredevil. He's a fussy old granny sometimes - how can you describe someone with a transporter phobia as a daredevil. But sometimes he can just say frak the rules and do as he pleases (such as in "Amok Time"). His contrariness is what makes him so specific and hard for an actor to get a bead on.