Dan,
The comments from the remarkably many forum members who have had rotator cuff surgery probably don't apply to you very well. The reason they had surgery and the nature of their surgery is different. Their surgery made them tighter and with shoulders, it takes a whole lot of work and time to make them properly loose. You are probably having surgery because you're too tight already, and surgery will immediately make you looser and have less pain. Absolutely, you will need PT afterwards and you should listen to the comments about being diligent about it. BUT my prediction is that you will feel remarkably better after your surgery and the doctors will caution you not to do too much. I can't think of any reason that you wouldn't be able to turn anything you want, once they give you the green light. Maybe they'll suggest you have a hoist or something to mount 40 pound blanks, but the turning part should be zero problem.