I agree on all points, but I don't see strong evidence for an easily teachable form of general rationality either, regardless of how intelligent the audience may be.

One other issue is that most people who have currently worked on developing rationality are themselves very intelligent. This sounds like it wouldn't particularly be a problem-- but as Eliezer wrote in My Way:

"If there are parts of my rationality that are visibly male, then there are probably other parts—perhaps harder to identify—that are tightly bound to growing up with Orthodox Jewish parents, or (cough) certain other unusual features of my life."

Intelligence definitely strikes me as one of those unusual features.

Perhaps it could be said that current rationality practices, designed by the highly intelligent and largely practiced by the same, require high intelligence, but it nevertheless seems far from clear that all rationality practices require high intelligence.