I figured out some of the issues.
Several of the male face Normal textures import as generic textures. Once I changed them to Normal textures, nearly all of the issues vanished.
My remaining issue may be the result of my severe lack of experience with UMA, or it might be a bug that crept in after an UMA update... I'm unsure.
This is all done in the HairStyles demo scene.
The issue is that the hair remains white when I set the color inside of the Dynamic Character Avatar script.
If I play the demo scene, open the UMARenderer, and change the Diffuse Color in the UM_HairPack_Mastermaterial, then the hair tints correctly.
Because it's not accepting the Dynamic Character Avatar tint, I'm unable to choose a color prior to spawning the UMA.
Any idea how to fix that?
I'm very new to UMA, so I don't know how all of the different scripts interrelate yet.