A mixture of Fridge Brilliance and Fridge Horror, Gamble's verbal abuse of his wife may come from the time he was a pimp. It also explains his weeniness as that's a deliberate attempt by him to become as least like his prior self as possible. It's just he's not very good at it since all of that is hovering under the surface. Bottom line, the pimp in him is still in there, just suppressed.
The marijuana dealers at the beginning being heavily armed is Rule of Funny and Rule of Cool but pot is a major part of cartel and Yardie operations. It's also possible they just were using the marijuana as an excuse to arrest them when they ran as well as started retaliating with heavy weapons fire.
Hoitz having the mad skills to curb-stomp a band of motorcycle hitmen singlehandedly may well have stemmed from the physical coordination derived from his dance lessons.
Gamble managed to attract every single attractive women before and during the movie with the exception of Terry's girlfriend who is somehow immune to his charms. However, it's stated the women he draws are not merely "attractive" but explicitly"hot" (ie. sexy). Terry's girlfriend is played by Lindsay Sloane who, though pretty, is more of an understated attractiveness than the obvious babes that seem to fall for Gamble.
