That's the whole point. Let's say we have 2 townspeople, 2 members of one cult, and one member of another cult left. Is the game over, or not? Or, even better, 3 people left: town/cult1/cult2.
Added 1 minute ago
And put a limit on the Mafia block as well; how is that better?
Added 2 minutes ago
I still don't understand the Cat. He collects the amulet and wins. So, the others lose – or will they play for their own victory, independent of the Cat? If the Cat is alive but hasn't collected the amulet, and only the Mafia is left, does he still win? The point of playing as the Cat is not to die and not let the Maniac find the amulet, and that's it – is that the victory condition?
Added 1 minute ago
What's the punishment? Immediate modkill, a warning, the team loses – what exactly? From my point of view, breaking a rule is acceptable if the benefits outweigh the consequences. And will the punishment be different if you reveal not your own role, but someone else's? (hint: it shouldn't be, otherwise, by the fact that there's no punishment, you can guess that someone was lying).
Added 5 minutes ago
Does the Mafia, who is a Seer and gets killed, have time to report the result to his team?