Indication of server-overridden settings in the options menu
Depending on the server, some of the settings may be overridden. If a player decides to change one of such settings in his client, he will think this is possible (and be able to change the client-side setting), but will not see the effect in game, which is likely to confuse the user.
To make this less likely, I propose that the settings that are overridden by the _currently-connected_ server should be disabled in the client's option GUI or, at least, be indicated in some way (probably some icon or being a different color). This will make configuration much easier.