As someone who's rotated through quite a few midwestern hospitals, I've never heard anyone use "Student Doctor" as a true title. Only as a "this is our student doctor, John Doe". When I introduce my medical students, I address them as Ms./Mr. so-and-so if I need to refer to them in fromt of a patient.
And while it's true that there are some total jerk residents out there that demand to be called "Dr." by students, I think it is totally reasonable as a student to expect to call a resident by his/her first name once you work with them. I think *most* residents are the same way. As a resident, I have even encountered other residents trying to pull the "I'm DR. So-and-so" when talking to other residents....which is completely ridiculous.
In the hospitals I work at, the floor RNs and OR staff who know me also call me by my first name, unless they are "old school" and call me doctor because they do that with every MD, or unless they don't know me and presumably don't know if I am resident vs. fellow vs. attending.