I'd just caution that shoulders are very complex and no matter how good your PT is, if he specializes in the spine, he might not be the best for you right at the moment. You speak so highly of him that hopefully he will know and admit when he's out of his depth - which is the problem I had this summer - and refer you to a shoulder specialist.

I was going to stay out of this discussion since everyone already knows what my opinion is - but can I say I'm glad that you made the decision you did? I really think that with neuromusculoskeletal issues, imaging, especially static imaging, is way more likely to come up with red herrings (like the neck DJD that we both have) and, worse, incidental findings on other body systems, than it is to nail down the actual source of your symptoms.