There is no one answer to your questions. It depends on the office. Some offices the OM is the decision maker, in others it is the DR. In some cases the DR is the decision maker but the OM must get all the information first, then present it to the Dr. I know one thing, you should never try to go around the OM because you will create a life long enemy. You need them to be on your side whether or not they are the decision maker. So I would start by trying to appeal to the OM. Of course you will always find situations where the DR is the one you need to get to, but can't get the OM to let you through. In those it's usually best to move on. But be flexible. Ask outright, "I have some information, should I direct it to you or to the DR?"