chris
Your words sound eminently sensible however they do rather ignore the evidence from those wonderful aids to understanding wings - wind tunnels.
In tunnels it is easy to actually measure the pressures all over the top and bottom surfaces of a wing at different angles of attack. (This is done by making many small holes in the surface of the wing and connecting these 'pressure tapping points' with tubes inside the wing to a bank of manometers or U tubes containing fluid. Naturally the fluid gets 'blown' up at the places where the pressure is increased and 'sucked' up where the pressure is lowered. The height of each column is of course proportional to the local pressure at the tapping point and providing you know the specific gravity of the fluid in the manometer the actual pressure - positive or negative - can easily be calculated.)
You will have to take my word for it that at angles below the stall the suctions are relatively much larger than the positive pressures. If you doubt my word (and why not for goodness sake) you could examine any suitable reference work on such activities.
When it comes to generating forces you are however very right that shape is less important than angle of attack. A traditional 'aerofoil' shape has the edge of course over a flat plate (which is in turn much better than an aerofoil flying inverted) when it comes to the suctions produced on the upper surface. Of course a 'good' shape also wins hands down with that marvellous measure of aerodynamic efficiency - the ratio between the lift generated and the drag generated or the L/D ratio.
In simply recording the facts of this life I do realise that I have done nothing to explain the facts. Such an explanation requires more mental horsepower than I was issued with.