In reply to Tigger:
A grade 1 or 2 is not a separation. Doing nothing is not bad advice (for a week or two to let it settle) but then it must be built back up to previous levels or beyond if it's likely to happen again.
They heal well and often do so on their own - just like an ankle sprain. But just like ankle sprains they can leave residual issues if not rehabbed properly.
A true separation could cause future complications if not looked at properly. But we are also not symmetrical and often have one side higher than the other, one leg longer than the other etc. It is not going to be able to be manipulated back into place.
A good osteo is as good as a good physio or a good chiro. If any of those are asking you to come back every week/fortnight to have things put back into place or re-aligned then leg it. If they're giving advice based around what you can do to help yourself, education, re-assurance and exercises based around what you want to do with the shoulder then all good.
These are all general comments. I haven't assessed you, obviously.