Re: Billy Sinclair
1. Suspenders. I don't think Billy wears a lot of hats.
2. Billy is extremely protective of his friends and thinks nothing of using the excess money that Luka gives him to spend it on people he cares about - if he can help with something, he will. (On the flip side, Billy is free with giving money but he doesn't like to give up possessions; he'll give you cash to buy clothes but he won't give you the shirt off his back.)
His worst trait is probably his aggression. He's quick to anger, he's violent in combat, and he can be unpredictably snappy and rude when he feels like his territory is being threatened. He's worked for years to try and calm that down, and it's working, but ... he's far from perfect.