I definitely agree that passion is the driving aspect of Mafia. In order to have a fun game, you have to want to have fun in the game.
It all depends on the theme for me, if its not a theme I enjoy, then I won't play.
While we have made beginner games etc in the past, they never _really_ work. It's fun to be on a team with a user who's better at the game than yourself, and that's how most of us learned how to play.
I'm not sure if Circus has done very much to make mafia more accessible...
I think evenly allocating beginners is a bad idea. Beginners should be assigned to mafia teams where they can have the maximum fun and information. Playing village as a newbie is boring unless the village leader is extraordinary.