The osteoarthritis is fairly normal...
Stave it off as long as you can with fish oil and other anti-inflammatory foods, ice if need be, plus not doing insane amounts of work on your shoulders. Sleep well, eat well, less stress, etc.
Not really anything to worry about IMO. Most people have degenerative changes in their lumbar spine... pain just doesn't affect a significant portion of the population. It's more common that people who weight lift properly do not have this pain so as long as your shoulders are balanced in strength / muscle mass (anterior-posterior) and keep up active flexibility you should be fine.