When few enough people want a preference that more people are likely to turn it on by mistake than deliberately, and when there's significant harm or confusion from turning it on by mistake, that's a sign that it's a bad preference. (See also: "Use external editor".)
Not to disagree with your general point, but that specific problem would be easy to handle by throwing a dialog with big red exclamation marks saying "WARNING! Arey you REALLY sure you know what you are doing?" when one is about to turn on such a feature. (Or only showing the controls when the user selects "expert mode".)
It would be fairly difficult to lock yourself out just by enabling the option, as part of enabling the option would be to login with the new authentication method. The biggest issue would be reseting credentials when the "what you have" is lost.
Respectfully,
Ryan Lane