Reading your post felt very weird to me, as if you were deliberately avoiding the obvious conclusion from your own examples! Do you really believe that people follow kosher or die in religious wars due to using abnormally explicit reasoning? The common thing about your examples is putting ideals over personal gain, not reasoning over instinct. Too much acting on explicitly stated values, not explicitly stated beliefs. In truth, using rationality for personal gain isn't nearly as dangerous as idealism/altruism and doesn't seem to require the precautions you go on to describe. If any of the crazy things I do failed to help me, I'd just stop doing them.

Which prompts a question to everyone: what crazy things do you do that help you? (Rather than help save the light cone or something.)