“Actually, I think that both FUDGE and Vampire have something like difficulty classes.”

They do, I was just hinting that the difficulty classes could be removed in favor of a simple "Failure" or "Success". I wouldn't suggest it personally (it's not as fun, and any character would be good at something as any other), just throwing it out there.

Also, I would just set the permissions for normal non-GM players to forbid post editing/deletion to prevent cheating.

The "one-liner" stuff is a bit of a dilemma though.