Howdy thought it might be useful to some if i posted here about my rehab. Interestingly it would seem that my shoulder woes have been as a result of developing core strength but only in a very basic sense. After i visited Hueco a few years ago I realised that i was WAY weaker than i thought but particularly in my core. In order to remedy this i basically hammered by abs with various different exercises and developed reasonable core strength (hold a parallel raise for a few seconds), but alas my training was far too basic and i've ended up training myself into a corner.
My Core is a bit digital its either on or off really and i'm currently unable to relax some areas whilst keeping others tight. In order to move freely on the step stuff (i'm very fond of the motherboard) you need to be able to release your upper core so that you can fully extend your shoulders and ribbs, whilst keeping your lower abdominals tight to maintain contact with your feet. Unfurtunatley through climbing very face on and repetitive leg raises on rings and the bar my core just goes very tight from bottom to top, and this means that when i extend my arm upwards my core is trying to pull my shoulders down, this causes the muscles in my rotator cuff to be stretched much further than they need be putting alot more strain on them which leads to the repeated pulling and tearing which i've experienced.
So now i'm working with a physio on a training plan which should take about 8 -20 weeks which will retrain my brain to allow different parts of my core to tense and relax accordingly. i'll post back and let you know how this develops, just thought it was an interesting place for the source of the problem rather than any muscualture in the joint of the shoulder itself.