Man, do I ever understand those feelings. I think I feel spreading at times myself although it is not as detectable as yours. That's just one of the things with this disease that sucks, it's different with everyone. There just needs to be so much more research into this.
From my experience, slow, steady, gentle movement does help and keeping "good" body parts moving does help for me as long as it is not painful or traumatic. But, that may not be the case for you.
It's hard to find a pattern with RSD/DRPS with me anyway. The only consistency so far seems to be with the nerve blocks and meds. I just can't take as high of a dosage of meds. as my Dr. would like.
I did try the spinal cord stimulator and was happy with the pain relief and subsequent push in range of motion afforded by that in physical therapy, but I did not like the trade off of loss of range of motion and pain in back and neck.