Lots of thoughts after reading all the good inputs from ya'll folks.
I agree that a "small" number of domains and theming could cover most deity concepts. But I feel that some of that list should have the basic "fundamentals"* included to kit bash most deities. That said, I would rather not use Light for all fire gods, some it would fit, others it would not.
Reflavoring is good concept, the Light cleric could be all about the concepts of warmth, enlightenment, showing the way, by their OTHER spell selections, while the Fire cleric is about burning, cleansing, lighting the beacons of Gondor.
But I still feel I am missing a few tools from the shed (hehe). Chaos, and the Elements.
Oh, and primordials are not worshipped (or at least they dont grant divine power). The world's nature spirits are their descendants, and those are more venerated, then worshiped. (Druids in my campaign rarely follow gods, more like spirit worship)
Finally, clerics are not just their domain. A Order cleric of Asmodeus would be different in play than an Order cleric of Bahamut. And besides, deities have several domains, Two clerics of Bahamut could have the same general worldview, but devoted themselves to a different aspect.
*of course we will never agree on what's fundamental and what isn't...