Unfortunately there isn’t a place to plug z factor into the brightness/contrast node - are there any work arounds for this so I can get brightness/contrast to fade with distance?
plug it into the Fac socket of the RGB Curve node, and set the curve to darken/contrast. Are you still looking for any compositing help with your project?
That sounds like it would work 
It wouldn’t hurt to have someone who could do pro-level compositing on XTIN Project. I don’t mind learning to do it myself so I’m not so ignorant about the various jobs that go into making a movie, but the trailer is showing so much potential right now that I don’t want to mess it up by tackling things I’m not fully up to speed on. If you’re interested, send me a PM. It’s not a lot of shots. There are 8 shots + the ending logo, and some of the shots are identical.
How do you set the curve to darken/contrast?
darken is a flatter slope, contrast is an S-curve. http://wiki.blender.org/index.php/Manual/Compositing_Nodes_Color#RGB_Curves_Node