We are using CLM for a guild as a DKP system. We use it in sealed and ascending item value mode. In this case the bidding is in whispers, or using the addon, but everyone can see other peoples standing if they use the addon. This can abuse the system if somebody bid the max amount of another player + 1 , to make sure, he/she receives the loot.

It would be great to add a feature, to handle this, like a toggle in the roster settings for enabling/disabling untrusted players to view other players DKP amount. Also, viewing self standings if the toggle is disabled would be great.

Opinion: I believe that limiting your players access to view their standing is a bad idea. Limiting player access to view their own stats and keep the guild/raid leaders accountable would lead to less trust and potentially more loot drama than you may be dealing with atm.

I don't believe I see an issue with a player bidding +1 the maximum of another. Presuming they are already the one with the highest DKP, they will only achieve maximum effeciency if the player they bid against bid their maximum amount.

This is not only impossible due to raiders having the data always (that's how autosync works), it's, as timj11dude said a bad idea. This is something that is not going to happen. You can achieve this by disabling sync completely (manual config) but then you are on your own as this is not a supported use case.