That's appealing, though there might be fringe cases or questions that would have to be settled beforehand. Is claiming town against the rules? Is a role claim against the rules or just abilities? Is it okay if you claim something that doesn't actually exist? Does dropping flavour clues count? What about lacing your sentences with key words from the wincon text? Or breadcrumbing but never explicitly pointing out the breadcrumb? But I think such a rule would be well worth trying— has any mod here enforced this rule?
Well, it's your game, so... Whatever you want?
Yes, fully against, no as that's a method to breadcrumb, yes, that's cheating in even a regular game, not allowed. I believe it might've been implemented somewhere, but I'm not sure where.
I'd strongly advise against rules like that. They're horrendous to enforce. Having a mafia ability sortof works, but not if the mafia has investigators (unless you're going for some Death Note variant)
The point is that you'd have to simply trust the player's to realize that giving away any bits of their role is against the rules. If they think that any of this is okay, since it's only slightly bending the rules, then you simply have poor sports. The game isn't about bending the rules. It's about finding scum. There ARE some games where it's about bending the rules. Then these types of things are okay. But, just make it clear that you just want them to try to play the game, not break it.
Is it seriously that hard to not break this rule? To not try to cheat? Really?