Can't comment on your wrist pain as I confess I am no expert on wrists and nmarman's advice seems good.

With regards to your shoulder, the more I read, the more inclined I am to think impingement syndrome. If your shoulder is looking fine on XR and MRI then it's definitely a likely possibility. I've treated numerous cases of shoulder impingement and all improved considerably (asymptomatic or 90%+ improved painwise). Bear in mind that it will take hard work and perseverance and because of the longstanding nature of your symptoms, there is no "quick fix."

Doing some scapula setting exercises and working on your posture will help to re-educate your muscles into the position they should be in. Drawing your shoulders back and down does this (although if you want some in-depth info I can email you an exercise sheet). Be very conscious of your posture and DO NOT SLOUCH or let your shoulders roll forwards. Relative rest - so don't do anything that aggravates it at the moment, lifting with shoulders in a poor slouched position or lifting anything heavy. What does a typical day consist of for you now? Do you spend long periods sitting or at a laptop or computer? If so, is it in a poor position? Sitting with a rolled up towel as a lumbar support in your lower back will automatically make you set your shoulders better and improve your posture.

Impingement syndrome is incredibly common but very treatable. Perhaps your pattern of symptoms confused the healthcare professionals you saw as mechanisms of injury etc can lead to different diagnoses with the information given. Sometimes I find the best way of testing a theory is to just start a bit of treatment and see if it helps! You sound very keen and proactive so I'd say work on scap setting and your posture and see how that changes your symptoms. Feel free to msg me if you want any more info.