Welp, grabbed another Kindle 3 as a replacement... cat knocked the other one off the headboard into the trashcan... I took it as a sign.

Maybe I'll rape parts, Cellular radio, SIM card (lol, dunno why, but everyone loves testing), etc. And keep it around as a spare screen just incase.
EDIT: Whee. Got the secondary kindle today, same hardware revision and all (Both have Rev. C on the motherboard) decided to drop the new battery into the 'new' kindle as hopefully not go through the same crap again. After dropping the new battery in, I got the 'critical battery' error, no prob > charge. I put the other battery into the old kindle for storage basically, and bink, green light and the kindle booted (since the other battery was at 50%). So my guess is the kindle requires some kind of power to go into charge mode, since the other one was stone dead, didn't have enough power to charge... sad no? Now I have two working kindle keyboards with 3g.
To anyone with the issue of a kindle not giving you a green light or responding to ANYTHING... see about borrowing the battery out of someone's kindle.