Like Der Fladermaus, I've run Eberron with no proof of Gods and alignment being guidelines rather than actual rules. However, once you remove Divine PCs and Core Races, it stops being D&D and starts into some realm of "other fantasy RPG" for me.
Arcana Evolved had both of those and that was part of the enjoyment. No arcane/divine split meant any caster could potentially heal. Some classes were even better at it.