"And of course the definition of the dogma states clearly that Mary shares our nature. Regarding "Original Sin," you might reflect on the fact that or Calvinis brethren do, or used to put much more stress on the doctrine that we do."
I know what the dogma says. The problem is that no matter what it says, it means that Panagia was ontologically different than the rest of us. I can say that the moon is made of green cheese. That doesn't make it so, especially if in the same breath I say that its made of rock. I sincerely believe that catholics can be excused if they conclude that the Theotokos was a of different order of humanity from the rest of us and proceed to improperly use terms like Co-Redemptrix.
As for the Calvinists and their interpretation of +Augustine's notions of Original Sin, well, you're absolutely right. They have raised it to a level far beyond anything that Rome has ever taught, though I'm not sure that their reading of +Augustine isn't a thoroughly fair one.
By the way, Robby, absent Rome's understanding of Original Sin, do you think the dogma of the Immaculate Conception is necessary? If so, why?