(1) I would argue that to some extent the first year or so of undergrad being common is something I've admired a lot about universities in the US. In India for instance, there is not as much common coursework in colleges, which I think is a bad thing.
(2) & (3) You are right, I shouldn't have posted without checking up on the facts. What I wanted to say was basically the destruction of the multi-tiered class structure corresponds roughly with the introduction of a common curriculum. A very valid argument of course remains as to when exactly educational paths should diverge, and I'm afraid both Adams & I are talking out of our hats without any real data.
Also, I think he is being somewhat dishonest in portraying the situation as a false binary of "scientists, thinkers and engineers who will propel civilization forward" and enterpreneurs. There is however a much larger group who will be neither. So while a rethink on education in college is good it is nowhere near as simple as Adams tries to claim it is.