[Notdan]

There's an awful lot here to already strongly agree with. Sort out the bell curve, make mortals more playable in mixed campaigns, and make combat less of a slog would be my biggest three.

I'd change the points system - make attunements cheaper (at least at character creation) and stats and forces more expensive. (Possibly make your forces in a realm dictate the maximum possibly level of associated stats, but decouple the two in terms of what XP buy you)

I'd make sure that the core book was sensibly arranged, and make sure that vital information that has since appeared in the supplements gets ported over. I'd have a "heaven" supplement dealing with all the minor Archangels and extra choirs, and a "hell" supplement for minor princes and bands.

Have Ethereals as a "third side", but a minor one - they can have a significant effect on local politics, are never going to realistically compete with Heaven or Hell.

I'd make sure that the word "grey" was spelled properly ;)