Sorry to make it seem bleak, but here's what the doc told me. AC joint is a "sprain". The level of the sprain is determined by how far the ligament has stretched and how far out of normal alignment the shoulder is. It never really "heals", as is the case with Danielsan, it just "feels better" over time. As far as rest goes, dude told me ice, no lifting, and 800mg ibuprofen 3x daily for a week and to go back in for X-rays on the 7th to determine the level of the sprain (1-3, 3 being the worst). Now, if it's torn, being that it's a ligament, it would require surgical repair. Judging by what you've already listed, symptomatically, I'd say it's a sprain and not a tear. A tear would render the shoulder useless and the deformity would be impossible to miss (your shoulder would drop as if your collarbone was broken).