Dude needs to tread lightly. Entries are all filled with categorical statements with creatures that have had a lot of varied abilities -- almost anything you can say about these beasts is going to mess with someone's version of them.
How about an approach to demons and devils that says, rather than "THIS IS WHAT THEY ARE," "This is what we mortals know of them."
This gives us modularity. Rather than saying "SUCCUBI ARE DEMONS!", we can say, "We know succubi are fiends that tempt people," and leave it up to individual DMs where these guys hail from. Extraplanar critters should be mysterious and weird -- if the only succubi that really exist in the worlds are things lonely wizards have summoned into the world, I'm not sure we'd know its taxonomy.
Overall, I'm fond of the idea of stripped-down abilities, and they seem to get the basic idea of each critter right (though I'd like a bit more of the 4e entropy/corruption dichotomy, but again, it can't be categorical -- succubi might be demons who corrupt and tempt and that doesn't mean they aren't Chaotic Evil engines of entropy, it just means their method of entropy isn't RARGH KILL SMASH).
Mostly I want the ability to use these things as I see fit in my own games, and going around saying things like "geherelths aren't the philosophical embodiment of evil!" is knocking down my sandcastles. On these guys, less is more -- be vague. Rely mostly on stats. They're all FIENDS, let individual DMs decide if they're whatever.