Russ......I've been watching this post for a while now. What type of doctors have you seen? GP.....orthopedist......chiro, etc?
I've had dreadful left shoulder pain for 2 years now and it's only recently I found out it's a "pinched nerve" in my neck that is causing such pain and radiating all the way down to my biceps. It seems I have a habit of "tilting" my neck when I'm typing or playing the piano and kind of "crunching" that nerve.
So.......you've had an X-ray, MRI, or some kind of confirmation from more than one source that it's a "torn rotator cuff?"
And, if it is, I would consider acupuncture. It worked well for me when I had knee problems.