You require a valid Passport to cross the Canadian border.
NO!
Yes you can.
Crossing the Canadian border would require a driver's license and passport.
Just the Nexus card suffices, but it's wise to have your passport when crossing the border, anyway.
yes you will need extra auto insurance for Mexico tho buy it in American border town as it is cheaper
Yes no matter what the distance you will need a passport to travel across the border.
Not if the flight is domestic
If you are Canadian you do not need a passport to enter Canada, though you may be asked to provide ID.
As of June 1st, 2009, Canadian Citizens require either a valid passport or enhanced driver's license to cross into the USA at a land border.
As of June 1, 2009, an American cannot drive across the Canadian border without a passport. Prior to that date, all you needed was a birth certificate and driver's license.
When border patrol scans your passport, they see your personal information such as your name, date of birth, nationality, and passport number. They also see any visa or entry stamps, as well as any alerts or restrictions associated with your passport.