Billing is not my best subject but I will jump in for a quick answer. We are getting some more experienced billers on-board soon.
My opinion:
First: Call them. Google it. You would be surprised what you find out. In addition feel free to ask on the forum.
Second: I am not sure I understand but you would not use the global code if the physician didn't provide the service. It must be the same physician or a partner (same group) to be included in the global period. Think of it this way. The global period is for the treatment that is normally expected during that time. If a different physician has to come in he is entitled to be paid. It most likely would be a consultation if it is another physician. If in doubt, again, call the payer to ask.
Third: Yes, and stay tuned, we are getting on here soon. In the mean time watch for those billing ladies to show up soon. I spoke with one just this week. I will text her today and see if she is registered for the forum.
Great questions. You are going to get to know your payers real well. Again, call them. Work on a relationship then share your info here. We need to know.