OTOH, my games tend to run into more of a grey area in terms of alignment. It is hard to determine an NPCs motivations. Detect Alignment will only work on outsiders, creatures without free will and those strongly aligned with a power (i.e. very high level clerics). The kind of world you describe here doesn't seem to fit in well with the kind of game I like to run.
It's interesting. Once you've read Dante's Inferno, you start to understand that even though a sense of right and wrong thrust people into Hell, it doesn't mean THEY thought they belonged there.
One of the first things I'm going to do for the blurb on the back of the book, because while reference to the Divine is accurate, it's not actually that relevant to the book. As someone else said, there's plenty of opportunities to flesh out Purgatory and Heaven. Oooh, I so want to write those!
But anyway, imagine this:
* You die, and find out that there is some more powerful divine power that considers your world to be "pagan" and thrusts you into hell. This is Dis, where clerics of a million religions end up.
* Worse, your GOD gets tossed into hell too. See, he wasn't as important as he thought he was. Now he's in the first circle of Hell, Limbo. Maybe you want to visit him since you're burning in Dis.
* Or perhaps you're a druid and you didn't even know about any other supreme divine being. Well, we can't be too harsh on the druid, so he gets placed in Limbo where all his spells work. Not knowing the Divine Presence is punishment enough.
Dante's Inferno definitely doles out the punishments. But in the Abyss, we expand on those tropes. It's less political allegory and more a living, breathing universe. There's plenty of room for gray. Although there's not a lot of room for good guys, there's certainly enough issues with keeping law and order.
In a lot of ways, playing in the Abyss is like playing in a gigantic prison. Everyone knows they're there to be punished. They know they did wrong. They know they chose the wrong side. And now they're stuck with each other in Hell. But that doesn't make Hell black and white, nor does it make it boring. They're stuck in hell along with very different groups, each with their own affiliations and punishments. They continue to live wretched lives -- that's the point, right? If you're mindless and static, it's not much punishment.
I'm not sure where I'm going with this other than to say that I think the Abyss has great potential for moral angst.