I'll just say what I know. For hairloss, my bro uses Propecia and since then he has not lost much-any hair. My best friend uses rogaine and it has halted his hairloss. With these products, you can't wait until your bald. You need to get it AS SOON AS you start losing your hair. Go see a doctor about that immediately if you like your hair. I check mine once a week and know that one day I'm going to have to make that call.
Second, you said you messed up your shoulder - rotator cuff? Well, I have 3 friends, 1 that did AS, that have messed that up. I think the worst thing is to go back on AS before you've healed 100%. AS will not make your bones or joints stronger (some may relieve the pain). Anyways, I suggest definitely adding a shoulder day and do all sorts of (lateral and front) raises to recover and strengthen your shoulder and rotator cuff. It's one of the most important upper body parts - definitely more important than the chest. Look at it. It connects everything. It's also one of the most likely things to (re)injure. AS will only increase the likeliness of that.
Oh well, good luck and best of luck to that shoulder.