I haven't looked at Smith yet, but the quote looks like parody to me. Since you seem to take it seriously, I'll respond. Awfully specific tests defying the predictions looks like data mining to me. I predict that these negative correlations are not replicable. The first seems to be the claim that verbal ability is not correlated with spatial ability, but this is a well-tested claim. As Shalizi mentions, psychometricians do look for separate skills and these are commonly accepted components. I wouldn't be terribly surprised if there were ones they completely missed, but these two are popular and positively correlated. The second example is a little more promising: maybe that scattered Xs test is independent of verbal ability, even though it looks like other skills that are not, but I doubt it.

With respect to self-discipline, I think you're experiencing some kind of halo effect. Not every positive mental trait should be called intelligence. Self-discipline is just not what people mean by intelligence. I knew that conscientiousness predicted GPAs, but I'd never heard such a strong claim. But it is true that a lot of people dismiss conscientiousness (and GPA) in favor of intelligence, and they seem to be making an error (or being risk-seeking).