1. Depends on the province.
2. According to
http://chealth.canoe.ca/channel_health_news_details.asp?channel_id=131&news_channel_id=131&news_id=30198 it is now only British Columbia, Yukon Territory, Manitoba, Ontario and Quebec who require a 3 month waiting time for new immigrants. I believe Manitoba and Quebec both make exceptions for pregnant women though and will cover pregnancy related care and childbirth even during the waiting time.
3. A combination of things. Routine medical care, hospitalization, necessary surgery etc. is covered but if you need a medical because of immigration, drivers license, insurance or other such purposes, you will pay. Routine tests are covered but there may be tests that you want done that are not routine and then you might have to pay. Necessary surgeries are covered but if you want surgery that isn't considered necessary, you may have to pay. Ambulances are not covered and medication is not covered but the prices are regulated so the pharmacies can not charge whatever they want. Dental care is not covered and eye glasses are not covered. However, most people have supplementary insurance through their work, might take 3 months or longer to become valid after you start paying, and this insurance may cover things like medication, dental work, eye glasses and other things.
4. See 2.
5. Buy travel insurance to cover you for emergencies or accidents during the 3 months or buy another insurance with more coverage if you want or you can just pay if you need care.
6. In many places in Canada, it can be hard to find a GP. The GP's I have had in Alberta, all of them I could see within a week. If you don't have a GP or you have an emergency, you can always go to a walk-in clinic and if it is not busy, you can be seen right away. If it is busy, you may have to wait a few hours to be seen. You can look up walk-in clinics in your area and before you go, you phone each one to ask how busy it is at that moment before you pick which one to go to. If you go to a hospital emergency room, you may have a long wait ahead of you unless they are very slow or you have a life threatening problem. If you need a non-life saving surgery, the waiting list can be long. Canadian health care works on a referral system so if you want to see a specialist, generally you have to see a regular doctor first and get a referral to see a specialist. The waiting list to see a specialist can also be long, sometimes several months but it depends on what it is and what kind of specialist you need. The referral is good for as long as you are dealing with the same health problem but if a long time passes or you have a different problem, you will need a new referral.
As you keep mentioning "free", I thought you should know that if you live in BC, you will pay monthly rates $57 for one person, $102 for a family of two and $114 for a family of three or more and in Ontario, it is based on your income, you can see the amount you would pay here:
http://www.rev.gov.on.ca/en/tax/healthpremium/rates.htmlApart from that, the health care is also paid from your taxes. Some provinces will charge you sales tax and some don't. Payroll taxes also vary between provinces.