So....if I leave the system unplugged, how should the pedal feel ?

At present, it is rock hard, but only seems to be locking the rear brakes. Virtually no effort at all being applied to the fronts.

But as I say...any time I tested at either key on, engine running, there was 12v power to the pump section.

And when I say hot.....you wouldnt be able to hold your hand on it for more than a few seconds. It is worryingly hot, and the heat is not radiating from the manifold.