Hmn. That's an interesting theory.

I do know, through the analyses of Central or Thalamic Pain Syndrome I've read, that trophically maintained pain often involves an overage of the acidic Substance P (you can read a lot about this at www.centralpain.org), but have not yet heard of the HCL link.

Have you posted about this over at the RSD/CRPS forum here? Those people are very knowledgable:

http://neurotalk.psychcentral.com/forum21.html