Workshop

Yes, I meant not additional non-player characters, but something like special daytime rights for these residents. For example, after winning at the casino at night (and bankrupting it:D), such an ordinary citizen could officially buy it during the day - then the previous owner becomes either an ordinary resident or a drunkard... Or something else along those lines.
Another idea: if two bosses meet at night (let's say, one goes to kill the other: accidentally, of course), they unite, like in a monopoly:D. The one who went to kill should remain the main one, and the second, in exchange for his life, agrees to cooperate:rolleyes:...
But the downside of such "cooperation" is that only one murder is possible per night for the two mafias (now effectively one). Although, in return, you could add the right to recruit (give it to the former boss).