Alpha - leader, egotistical, authoritarian - must be placated/ego stroked
Beta - second in command, strong willed, diplomatic - needs to be persuaded/shown benefits
Omega - soldier, humble, suggestible - will cave in to aggression/orders"tough love"
Omegas are not outcasts or criminals by default. These are personality types, they don't reflect personal beliefs, social hierarchy, or life choices. A gangster can just as easily be an alpha as a cop can be an omega. Characters are not limited to just one of these types either. There are even some characters that are all three; upon whom the social enhancer's pheromones are useless, but get some interesting responses. You just have to talk to people, watch their expressions, and do a little digging into their background in order to get what you want without the aug. It's not easy. However, there are certain conversation options that are only available if you have the social enhancer, so the aug is worth getting.
You know what, it's a lot easier if you think of it like South Park characters.
Alpha - Cartman
Beta - Stan
Omega - Butters