So the basic premise of your writeup is you are trying to judge how smart people are based on what they submit to this site and the content of their comments. I am not so sure I agree with that. It seems to me that starting a company requires dedication, technical smarts and technical vision. All that a good comment or submission tells you is that the submitter spends a lot of time surfing the web and is articulate. Unless you have solid reasons to believe that the two sets of qualities are strongly correlated, I am not so sure you should be even consider using this as a metric. Having worked in Silicon Valley for some time now, I can say that some of the smartest people around here have inadequate language (and by implication -- commenting) skills. Quality of people's resumes are likely to provide a stronger indicator.
Interesting. Perhaps they should be performing traffic analysis to see who's busy, and who's not?
I love to debate (reddit has saved my wife a regular earful), but I can't imagine surfing when I'm really "in the zone". I tend to do more directed documentation queries and explicitly avoid sites like reddit where I'm likely to become mired.
So yeah, for me posting frequency is inversely correlated with how busy I am. On the other hand, all of that reading, researching and debating generates a lot of new ideas.