well, i know that 4 mafia is standard for a 20 man game, so the extra 3 people might give an extra mafia, howver 6 is probably possible, i think that 7 is excessive though.
4 scum in 20 is on the low end. Very low. If there are only 4 mafia then there will be almost as many neutrals. Or a second mafia. Or a SK.
if mafia dont know each other yet then then we are able to interrogate without fear that the mafia can control it as easily you say, and we might acatually have a mafia up for interrogation/prosection, if hey DO know each other then you are correct, and we really cant expect to get a scum lynch tommorow with that system.
There was a gap between when role PMs were sent and when twilight started. I'm sure flubb remembers it. I think that gap was approximately the length of a normal night phase. I will assume mafia were chillaxing and plotting in their QT unless Pyro tells us otherwise.