No, you do not need a passport to fly within the United States of America. If you are going out of the country, you will need to get one.
Yes.
I would say yes. You would have to cross the Windsor/Detroit border crossing, and as of 2009 we Canadians need a passport to cross the American border. In fact, if you left from Pearson, in Toronto, you'd need a passport to board the plane.
Yes, you need a passport to fly internationally.
Yes, you need a passport to fly internationally.
Yes, you need a passport to fly out of Tijuana.
Yes, babies need a passport to fly internationally.
Yes. You need a passport to fly anywhere.
Yes, children need a passport to fly internationally.
Yes, children need a passport to fly to Mexico.
Yes, minors need a passport to fly to Mexico.
Yes, you need a passport to fly from Tijuana to Guadalajara.
Yes you need a valid passport to fly from Glasgow to Spain.