No, I'm pretty sure Einstein-level intelligence is rarer than that, which is why I put my lower bound at 1 in 10^4 (i.e. the top three students in a region's worth of high schools). I'm not sure it's much rarer, though -- we don't have an outstandingly good idea of what makes an Einstein other than sheer weight of g, and we don't even know that people with the prerequisites of an Einstein would consistently have been funneled into fields where they'd have the opportunity to do things like make famous discoveries in physics.

As to the latter, I kind of suspect not. Of the three smartest people in my (pretty large) high school as measured by the National Merit Scholarship program -- probably the only American program that looks for exceptional g on a national scale that late in life, though any number of programs exist for gifted children -- one now works for Google's IT department and a second was, last I heard, going into an art school. The third is... well, not in physics or math either. Not sure what the equivalent of Google would have been in 1935 -- maybe something in mechanical engineering? -- but I doubt the hard sciences then selected for intelligence much better than they do now.