Just a quick little add on to the thought about the multiple roles; I was thinking maybe it could be done like Dead Before Daylight instead of Town of Salem.
Let me explain.
In Town of Salem, there's a group of people and every person has a role. But in Dead Before Daylight, there's a group of normal people but only the killer changes.
So, what I'm saying is, instead of having a ton of random roles in one game, I think it should be where all of the crewmates remain normal crewmates, but the impostors have a chance of being a different impostor role.
For example:
A 10 person game - 8 crewmates, and 2 Serial Killers
A 10 person game - 8 crewmates, 1 Alien, and 1 Wraith
A 6 person game - 5 crewmates, and 1 Demon
(I still don't know what the other impostor roles would be so I'm making random ones lmao)
So, the crewmates have to adapt to which Impostors they have to deal with.
Thanks for reading :^)