blue...
Your first question: if you enjoy medical management of patients, orthopedics is not the field for you. We routinely consult medicine to manage diabetes, pneumonia, SOB, you name it. Outside of pain meds, NSAIDs and antibiotics, orthopods rarely prescribe any other class of medication. As far as trauma, we deal exclusively with musculoskeletal trauma. There is always a tauma surgeon (general surgeon) in charge of polytraumas who manage the patient's hemodynamic status and overall care. These surgeons consult various services like ortho, neurosurg, urology, etc. for specific injuries that fall within the realm of these fields. So as an orthopaedic traumatologist, your role is strictly as a consultant. You do a year of general surgery, but you soon forget much of it after a couple of years as an ortho resident. There is so much to learn in ortho that you simply don't have time to keep up with problems that a gen surg or internist deals with.
Your 2nd question: it is true that you can shape your practice any way you want...put a "will see puss" sign on your door and you'll have the busiest practice in town. In a metropolitan area, there is competition and you may have to see problems that are 'undesirable' to make a living or build your practice. Once you're established, which can take anywhere from 1-5 years depending on you and the area you live in, you can be more selective. You can be a generalist, do 50% hand, 50% general...or 20% hand, 20% foot, 60% general...you get the idea. You can do a hand fellowship and still do 50% general ortho. Or you can do a hand fellowship and do strictly hand. So bottom line is that you can shape your practice anyway you want, but initially when you start out, you cannot be super-selective because you're the new guy and may have to see patients you wouldn't want to.