The CC doesn't need a PRAM battery to boot. I didn't have one installed when I tested mine. (if you have one installed and it's dead, it might be wise to remove it though...)

I don't know of any other common points, but there are a lot of vias by C6. If you're really patient, my picture above with the chips removed shows where all the traces go. You could cross-reference this with the bottom of the board to verify all connections that are made through those vias. That's what I did -- I took a picture of the top and bottom and slowly tested every via.

Oh, just saw your new reply...nice, congrats! If you're comfortable doing so, it might be wise to remove them anyway...U7 had some gunk underneath from the capacitor leakage that felt good to clean up.