No Great Wheel. No Blood War, no demon princes, no archdevils.
There are only 2 deities remaining, cooperatively holding creation together. Cleric Domains fall under specific orders of the Dyadic church.
Planes are arranged in a concentric layers, also, but starting at the center and going out is the Sunless Fire (elemental fire, devils, fire giants), the Darkness Below Stone (elemental earth, “underdark”, hill giants), The World (elemental water, the campaign setting), the Hanging Mountains (elemental air, “frostfell”, cloud and frost giants ), the Vault of Stars (“Astral Sea”, demons, far realm pockets, celestials).
Like others mentioned earlier, I too merged Shadowfell and Feywild and call Otherworld, I read that in the DMG and swiped that. Otherworld is parallel to every concentric plane.
Elemental Entropy is also parallel to every concentric plane
Dragons are not intelligent to be spellcasting. No Chromatic or metallic scale exterior.
No drow, shifted the spider-theme onto aranea.
Standard “evil” humanoids (gnolls, orcs, goblinoids, etc. and others) are infected by a curse from outer evils beyond the Vault of Stars. The curse is held in place by a MacGuffin (cough Starseed) and if it can be found and destroyed that tribe under that curse is cured and lose the compulsion for destruction, violence, and chaos. The “cursed” are also compelled to convert everyone not under the influence of their clan’s Starseed.
Only dwarf is hill dwarf, only elf is high elf, only gnome is deep gnome. Halflings must come from Otherworld (borrowing this from Birthright). I came up with breath weapon replacements for dragonborn.