Hi there,

>>Are grains  non-paleo?  ( is moderate consumption OK ?)
>>(hunter-gatherers probably gathered grass seeds - didnt they ?)

Correct. Grains are non-paleo. Yeah, hunter-gatherers may have collected a
few grass seeds here and there, but they certainly didn't have the time or
inclination to grow a crop of wheat/rye/barley/rice in a field then mill it
down into some gummy starch and consume it and then roll around due to upset
metabolism.

>>Which grains are best ( or least problematic)  ?

One is no better than the other really. Wheat may generally be an allergin
in more people, but only because it is more widely eaten.

>>Is  rye better than wheat ?
 Ditto