Issues from old collarbone fracture

Hi All,
This is my first post here so hello to everyone and thank you in advance for any help or advice that can be offered.

Approximately 6-7 years ago I fractured my collarbone (clean break) and have always believed it has not quite healed correctly. A few weeks after it had healed I had to go back to the hospital so they could grind down a bit of bone that was causing tenting on the top of my shoulder. Now, several years on it still does not seem to sit right, if I put my back against a wall I can feel my shoulderblade pushing into the wall (only very slightly, not like a winged scapula).

Since the injury I have lost lots of strength in my left arm and shoulder as I know I have been favouring the other side of my body (fortunately I am right-handed) and recently I have wanted to rebuild the strength in my arm and shoulder.

I am an active person and do weekly martial arts and occasional swimming. I do have full movement in my shoulder but certain movements, such as arm rotations or lifts out to the side of my body, produce a disconcerting "crackling" and popping within the joint. There is no pain associated with this but I do not want to cause further damage if I start exercising the joint using weights etc.

I believe it is likely to be cartilage or scar tissue grinding and not bone, as there is no pain associated, but I would like some advice on whether I am safe to up my level of exercise or should seek medical advice. I am based in the UK so medical advice is free but will take a long time with different referrals etc..

Thank you,
Tom