Robert > I don't say these things to boast or to irritate, but to ask
whether my reactions (or lack of them) are really that uncommon?  Is
this list (or rather, the posts made to it) representative of the
general population when it comes to diet sensitivity, or is there a
higher concentration of  people here with high food sensitivities?

I'm not sensitive to any of the generally accepted paleo foods.  Grains,
beans, dairy, trans fats, chocolate, alcohol, etc. *do* cause problems. 
It's very simple, cut and dried for me.