Progress report: My chain moves again! But...not exactly the way I'd like it to. I attempted to adjust my derailleur per preston and srvblues advice which got me very close but not perfect. I can easily go from small to medium and back to small with no problems and little to no rubbing using all the rear gears. But, shifting to the big ring is still a problem. I can get it to shift, but I need to be on one of the larger gears in the rear to get it to move at all. Otherwise, the cage barely makes contact with the chain. I have my high stop adjustment screw backed all the way out. The derailleur just won't move any more. I also tried lowering the derailleur but it is already as low as it can go. Any lower and it hits the middle ring when I downshift. I thought that if I toed the derailleur in a bit (front end towards the frame moving the backend near the chain) that it might help but it didn't seem to make a difference and just caused more rubbing in other gears.

Based on this, does it sound like I need a new derailleur? It works good enough get me by for the moment but it's going to get real old shifting so much just to get onto the big ring.