Ok so I finally got the time to read them over, although I won't be able to work on cleaning up the lore dump tonight :(
Morgan - Looks fine for the setting nothing stands out as off or wrong, even could fit a few npc's I know about into it as former masters and such.
Zaikudo - he can be an Aasimar from birth even to human parents, and would even be seen as a blessing from the sacred fire, but a change after birth is kind of much. As for the visions/premonitions I think that would fit more into a Kalashtar
than an Aasimar But maybe you could get some interventions along the way. Also with the new Aasimar you would have a celestial revelation of Radiant Consumption (I would suggest the updated one as you no longer hurt yourself with burning eyes mode)