Personally I think
Dash&Thump in post #9 already has hit it on the head.
The viscosity is the property that allows the air to seperate at the trailing edge and not come back up and join the other stream in the opposite place to the separation point at the front. I think....
No viscosity, no trailing edge separation.
So, for a flat plate at an angle of attack, lower pressure on top, same higher pressure on the bottom.
No lift, just drag.
He's probably right, otherwise why would we fuss so much about Reynolds numbers?
CJ