Jerry Seinfeld is undoubtedly the most STP comic ever to stand up. Compared to Bill Hicks - the man who told sections of his audience to go kill themselves, definitely an intuitor of some variant.
I don't think you have a very good grasp of extraverted sensation, but then again, most don't.
Yes, it is interesting, because Seinfeld clearly is clearly a Ti-Se user (or some kind of sensor/thinker), the way he observes his sensory surroundings and deconstructs them, but he isn't visceral at all. He's extremely clean.
Meanwhile, someone super 'N' like Bill Hicks, as you mention, used a lot of violent imagery. Louis CK, clearly an intuitor as well (whether he's N-dom or not, I won't get into) makes a lot of disgusting jokes. I think he has a bit where he beats a man to death with a tire iron and jacks off on his corpse, because the man's bumper sticker said: tell your girlfriend I said 'thanks'.
While I don't think this is a rule, I suspect people who suppress their sensing functions, tend to express it in grotesque and unusual ways, since it's underdeveloped.
Edit: As for type and comedy, I find the enneagram helpful for identifying comedians too. I suspect most comedians are typed somewhere within the head triad. They're usually 6's too. All that 6 neurosis is comedy gold. Eddie Murphy is a good example of a 7 comedian, and I would say Demetri Martin is a good example of a 5...but most of the heavyweights are 6's.
I agree though, ENTP's are a great type for stand-up. Much of comedy is about examining familiar things in unfamiliar ways, making absurd connections, and rapid fire verbalization.
