Hello, another Canadian here. These are my experiences. I have a chronic condition that requires continuing Dr. checks every 3 - 6 months, which also involves blood tests and an occasional ultrasound or x-ray, or scan. All these appointments and tests are free (mind you we all contribute to our national health plan through our income tax). If I move, or for some reason don't like my present Dr. I can change, without having to get approval from any insurance company or government agency. Where some problems have come up is when patients need to be seen by a specialist, sometimes you might have to wait a few months for an appointment.
Another example - close friend suffered what turned out to be a minor stroke. He went to the local hospital emerg. was seen immediately and was given a variety of tests immediately. He was diagnosed that day, was given some medication, and was seen by his family Dr. within a day with regular follow-ups now every 2 months.
When we all reach 65, all of our medication is free, except for some newer ones, and even those, if the Dr. shows that the conventional medication has not helped, then we can get the newer ones.
When we travel out of country we purchase medical insurance to cover any mishaps.
For anyone visiting Canada, they need to have their own medical insurance. The hospitals and Drs. will expect payment and then the visitor will have to claim for payment from their own medical insurance.