Finding the answer to my question ~ What makes a divine, and where does a divine stop being a divine?
The bare minimum for a Divine to still be a Divine appears to be:
14 Cleric or Favored Soul levels along with Quicken for Epic Hard/Elite
14 of the 15 maximum levels of heal spells
100% chance to cast Resurrection
Quicken metamagic to be applied to spells that cannot afford fail concentration checks
The ability to gain either blade barrier and/cl // or/fvs mass cure moderate wounds allowing possible mass raid healing
Mass Cure Light Wounds cast at level 14 + any epic destiny additional levels
Single target deathward and freedom of movement spells with nice duration
The ability to choose divine favor and divine might to gain full BAB when desired
The ability to cast resist energy with nice duration
100% chance to scroll great restoration
This allows a 14 / 6 split as the maximum divine "heavy splash."
Anything past this, should probably be considered more of a "self healing" build;
comparable to an efficient pally or ranger.
I wonder what a cleric 6 / favored soul 14 laser build would be like?