I agree with your feelings about RSD spreading. I have a number of the same issues.
My RSD is from an accident effecting my left arm with burning pain too. It's now spreading to my face and down to my body and leg. I get numbness in my face and eye twitch. All on the left side too.
I also have degenerative cerebral atrophy effecting my motor skills, speech and balance so when my leg starts getting that tingling pain and I'm standing or trying to walk I fall.
I'm writing this just so you wont feel alone with this monster...