Unless JMS was hinting at some kind of super-intelligence power that this Clark has, I too wondered about that equation. As for the other professions, my guess it that his tenure in those jobs was so short that people would forget? Maybe JMS will address the repercussions of those public attempts in future volumes.
The football incident, in particular, should be a major tip-off to anybody looking for a Superman alter-ego...not to mention the fact that he only starts wearing glasses at the end of the storyline...
Regarding the equation: it's hard to see how innate intelligence would have been enough to solve the equation. It was a scientific question that involved some very specific background information.