Have you considered that there might be a connection between the Fireman and Prometheus, the helpful Titan who gave man the gift of fire at his own expense? I know there's no evidence that the Fireman is suffering, but he does seem like a kind of benefactor to humanity.
I thought about Prometheus, too. In this case, I believe the Fireman to be more akin to Zeus, with us - that is, humanity - being Prometheus, having stolen the fire of the gods with the use of nuclear weapons.
That, at least, is one of the ideas I think to come from Episode 8.
Or, in simple terms, "Play with fire and you get burned".
Which takes us right back to the other interpretation of "Fireman", one who keeps people safe from fire. So, I guess he's both.