yeah in this the slugs are the mafia and then just the villagers. your number 1 is right, a couple games ago juice brought up the recruiting. Basically the slugs will have the option to not kill a person one (or maybe more depending on how many recruits allowed) and instead recruit them over to the slugs. It's a twist that really throws a wrench into the regular style of play/thinking.
Yeah the way I usually played those were separate roles that could be given to players either in the mafia or their own faction.
Gotta say I don't like knowing the ratio of slugs to villagers but hey will make the game easier.