Yes, that's probably the best way to view the development of that article. However, I can't go into that much detail myself because I certainly don't have the time to do that much research. That quote from Iliad is rather odd. Homer seems to be refering to Hesiod's earlier Theogony; but the details are different. The Perseus Digital Library (whose pages take some time to load; so for anybody reading this, be patient) translates Homer's quote just as you say (line 14 onwards), and has this to say for Theogony (line 720 onwards). I'm no classicist, but I'd be weary of that bit of text - it is certinly odd and probably should not be taken at face value so naïvely. As you say, everywhere else (as far as I know) he refers to the underworld as the "domain of hades". As for Erebus, the quotes from Iliad (under the heading: 3 from Homer, Iliad), at face value, seem to indicate that it is a place. But this is merely a misunderstanding of what Erebus is. Erebus is the gloom, the darkness of the underworld, the "place of dark mists" as you put it. Replace "Erebus" with "darkness of the underworld" or the like and the quotes make just as much sense as the assumption that Erebus is a physical location. However, I don't know of any source that explicitly states that it is a location in the underworld; so, again, where does that quote come from?