(Disclaimer: I'm currently acting an auditor of bustadice, and can cryptographically verify the bet-results. However it's only really got decent guarantees for investors, for players they are much better off verifying their own bets. It's also only a useful service if you believe I'm independent from Daniel, which while true, I wouldn't blame anyone for doubting... But fortunately players can trustlessly verify their own bets )
There is no way for a game to be guaranteed or provable fair to investors.
I don't understand why you would put yourself in such a sticky spot on purpose?
Important: There is no guarantee to investors on provably fair sites because the owner can still play within the rules and "beat you fairly". These sites are only proveably fair to players... NOT investors, it isn't possible to prove. Unless I'm outside on something new.