As far as the definition of rural goes, I would strongly encourage you to steer away from trying to completely understand it, because it's a moving target. If you are a researcher, you need sort of a Statistics Canada definition. If you're a health planner, you need more a style of practice definition. If you're a geographer, the simplest....
When we at the Society of Rural Physicians were first distributing our journal, we sent it to every address that had zeros in its postal code. Some of those were addresses of cottages belonging to people who were working in Toronto. The most useful definition and the hardest one to get to has to do with what I referred to earlier as physicians who have a comparable level of responsibility. That's very hard to tease out from geography or from population size.
As the physician workforce shrinks, a lot of communities find their physicians taking on more and more responsibility, and therefore becoming rural in a sense, although nothing around them has changed. But I think the philosophy of the Society of Rural Physicians' definition is the one that works the best. Some people are clearly rural by virtue of their geography. On the other hand, a physician who works in Whitehorse and who is merely doing psychotherapy in his office does not have the same responsibility as a physician in the same community who may be doing obstetrics and emergency room work, etc.