[Steward]

Originally Posted by Almagesto

Have you consider taking a glance at Tyrants of the Nine Hells? It could prove to be a pretty good reference to what you're aiming at.

There are several references to that book in the spoiler section:

While I browsed the classes I stumbled upon warlock, which led me to Hellfire warlock, which ultimately led me to Fiendish Codex 2.

and

Not that much, but in comparison with Hades’ realm, which had 5 rivers, each assigned to a specific task, in Fiendish Codex II (henceforth FCII) uses the Styx for just about any task necessary.

and

Normally this would be Satan’s Citadel, but I’m gonna stick the FCII version of it.

EDIT:

As far as the errata goes, it looks pretty workable to me. I actually liked the cosmology presented in FCII and your changes do a good job altering the flavor to make it even closer to the classical mythology. My only concern is that the first two tables are kind of confusing to parse since they're very different from traditional D & D tables. Table 3 was really good but I've read the first two twice and I can't make any sense of how they would work mechanically.