I broke my shoulder once bicycling, (Glenoid Fracture), which while not the same as a collar bone injury, presented a lot of the same problems you will face.
First, if you have surgery or not, its probably not going to improve your recovery time all that significantly, or make things more or less comfortable. If it is a really bad break requiring surgery, fine, but if it isn't, you're still looking at roughly a 6 week recovery time. Many collar bone breaks are NOT treated surgically, and often, less is more. Surgery may lead to its own set of complications regarding muscle recovery, range of motion, etc., and won't get you up and running any faster.
Coughing is probably going to hurt quite a bit. But, if you can keep the shoulder stable, you might be able to reduce that pain somewhat. Also realize that the pain isn't making your shoulder any worse, and coughing is important. I was surprised how quickly I got used to it. I stuck with Ibuprofen for pain, not wanting to take more for fear of developing dependency.
The one thing that hurt A LOT was Chest PT. I don't know what methods you use, but manual PT is going to be incredibly difficult. The pounding may also not be good for the healing of the bone in the first few weeks.
Don't take six weeks off from physical activity. I rode my bike indoors on a trainer while my bone healed. just stay seated, and don't put pressure on that shoulder.
Lastly, DO THE PHYSICAL THERAPY! If you leave your arm in a sling for six weeks, you aren't going to be able to move it, and will lose a significant amount of range of motion. Do whatever exercises they give you, and do them often.
Best of luck.
Chris
