This is fantastic! I have been following ToyRig for some time and was completely shocked when I came across this topic today. You've done a wonderful job, and the plug in works in R21 (that did not expect either, given how long ago you made the original post.)
I want to echo what everfresh wrote and encourage you to make a character template for this rig. I bet some at MAXON would even offer some help and encouragement!