Corey; Thanks! I'll address your tips here
1. The color of the forcefields. /sigh That's my color blindness showing through, once again. I'll fix that soon in either the original model or in Photoshop. Thanks for pointing that out cuz I never would've spotted it myself.
2. I didn't have a lot of time yesterday due to a family emergency, but I did try messing around with the lightcap strength and shadow settings and kept either ending up with pretty much what you see or a totally washed out model with no shadows on top at all. I'm going to study up more on lightcap shadows and in the meantime I'll just darken them a little in PS.
3. Those pinlights are something I definitely want to do and I really wish there were a way to do that directly in Zbrush. But I'll figure out how to do it in PS for sure and post here as soon as possible. Thanks for bringing this up, as that's one of the details I originally wanted and totally forgot about.
4. The fighter idea is great. I'll play around with that one too!
Ericshawn and Ezra; Thanks guys!
Glenn; Thank you so much, man! That's another thing I didn't even think about! See below.
Took Glenn's IDEA (caps intentional for the awesomeness of the tip) and ran with it! It created a (in my opinion) much more subtle but at the same time more dramatic backgound. Five total minutes in PS and this is what I have now: