1:
I guess 1 mafia team with 6-ish members. There may be a traitor or two to weaken the mafia roster, or other weakening options available, as reasoned by Decagon. To punish mass-claiming, most games seem to have a mafia roleblocker these days, so I will also assume there is one.
But given the mention of two football teams, there may even be two mafia teams around.
2:
I guess 1 serial killer. This makes it 7 scum players in total, which seems about right.
3:
There should be a hint if there is. Apart from the faction thread plurative interpretation I have seen no such hint. As such I guess no. Hints may come tonight though!
4:
I got more info out of Uggor than anyone else in the rainbow game as he scumslipped once and accidentally outed Simca another.
I was just too much of a coward to act on it, and wasn't cut-throat enough to do so.
But this means I find him very useful alive as mafia. And as town, he is useful for making bandwagons, and obviously, a town player that actually speaks.
In short... I do not want him lynched.