Yes. A Passport (or a Passport Card or Enhanced Driver's Licence if coming by land) is required for crossing the border into Canada unless you are 15 or younger.

That is correct. Children under 16 only require a birth certificate if coming by land ( by air everyone is required to have a passport ). They may use a copied version of birth certificate but it must be a notarized to be accepted.

Yes you may use passport cards for all land travel. Passport cards are applied for issued in your home country.

No. You must apply for separate Visa to enter Canada. You may get information on ETA's or Visitor Visa to enter Canada, here http://www.cic.gc.ca/english/visit/index.asp

There are a few places very close to the border where you will be able to pick up American cell phone towers but beware as you will be bounced from tower to tower in this area. For the most part you will need to contact your service provider and add international plan for the lenght of your stay. This can easily be done online or through your providers app on your smart phone. If you do not set up an international plan please be sure to turn off roaming features for both phone and data as the roaming cost will be quite high.

Yes, you should probably change your U.S. to Canadian dollars. While most Toronto businesses will accept American money graciously, exchange rates can vary.