It's largely figurative anyway so it's still valid. But, if I were to change it, one thing that's dramatically different from the era of Heinlein's youth is th

It's largely figurative anyway so it's still valid. But, if I were to change it, one thing that's dramatically different from the era of Heinlein's youth is that the world is a much smaller place that it once must have seemed. Global communication is trivial, cultures are blending together, travel to anywhere is within the reach of the general population, and the activities of civilization are great enough to affect the ecology of the planet as a whole. So the two new additions I'd add are "survive and thrive in any culture" and "understand civilizational trends", whether they be political, ecological, technological, or otherwise.