I've seen a few of the following features greyed-out, but only a couple of the features allow me to grey them out so that a user can't tamper with the changes:
Under, Users & Groups...Login Options... - display login windows as: name & password - show fast user switching
Under, Energy Saver... -Turn displays off after (both tabs "battery" & "power adapter")
Under, Sharing... -Remote Login
Under App Store... -automatically check for updates
If anyone has tips on greying-out these areas, that would be great to test
