You're very correct! The American Medical Association actually suggests alternative care therapies, including Chiropractic, before surgery. However, you do see some misconceptions floating around still.
I had the benefit of talking with a very open minded neurologist and he stated that he used to despise the idea of referring to a chiropractor. However, In the recent years with the move toward evidence based practice - the chiropractor serves a very vital role.
I suppose with an NP, you can sort of focus in any field you see fit for your interest. Personally, I already have extensive orthopedic knowledge and would be quite upset relearning everything in my field just for prescription privilege.
Personally, I love the elderly and wish to work solely in geriatrics. My elder patients, on average, have about 10 different medications and how is someone suppose to care for that if they have no control over pharmaceuticalls? Chiropractors, by law, cannot suggest that a patient discontinue a medication, BUT an NP can suggest a less dangerous alternative and write out the prescription - that's the main reason I'm doing what I am. It's all about the patient.