The left spotty figure can render properly, but if I change a light to "point to" and point it at that figure the spots appear, sometimes more, sometimes less, depending on how I move the light around.

 

Ahh. You cannot use point at using an infinite light. Why? Because it's infinite..LOL (sorry) I cannot give you the scientific reason but if you change from a "point at" spot to an infinite you will understand why. The new infinite will end up 180 degrees out of whack. Infinite on a Depth Map Shadow light with a map size of only 256 will be ragged around the edges. Usually you need all the 4096 map for an infinite. Better to swap to a spot light. Then use "Point at". Raise your mapsize to 1024 from 256.

This should get rid of the spotting.

You cannot use Point lights with those skin shaders either. Not as the mainlight that is. Just thought I'd add that.

 

After testing P4, I would change your Depth Map Light to  RayTrace. Check "use Ray Trace" in Rendersettings. Render This should fix spotty automatically.