Throw in one additional question. Burt introduced us to the concept of the "Smart One", and offered the concept that the intelligence of a zombie is dependent on their intelligence before they were bit. That always struck me as a big logical leap, based on his story of having spent the whole outbreak locked in the bathroom. Maybe he does have some knowledge he hasn't shared yet.

As for Radon Labs, I've long thought that it would figure into the story again before the story ends.