Ok, so I’ve properly begun my Alias training now, and I see that some of the questions I asked doesn’t make sense. Kudos to those who managed to answer them anyway! 
Next question is still (unfortunately) a keypoint curve question:
How can I “lock” the center of the radius of an arc to a certain position? (I know I can move the pivot at then reposition the arc at my specified fixed point, but I would like to be able to edit the arc in place without having the center of the radius ever move.)
But I also have one for the surface geeks out there:
How can I increase the accuracy of trimmed surfaces? I have tried to rebuild the originating surfaces and curves in a few ways, but nothing seems to matter in this particular instance. It’s also weird that the surface evaluation tool complains about angle deviations in tangency alignment, but the surfaces are only aligned with position.
PS. Wow, Evangelist, did you model that head in Alias, or are you just painting it in Alias? Either way seem rather masochistic, though. 