I like the "psycho" side of things. You're right, not all games should have role naivety, because it might scare of new players. But for those that do... there's so much potential for Mods creating havoc:
- Multiple Seers
- Multiple Lovers
- False Seers
- Separate Werewolf groups
- Make everybody a wolf in separate groups, last group alive wins.
- Multiple Rangers/Hunters
- Making everybody gifted.
- No gifteds.
- Make every villager a cobbler.
- Shirriffs.
- False Shirriffs??
Not to mention new roles just to muck people about.