To fly into Mexico you HAVE to have a passport. As of right now the only way you can get into Mexico without a passport is by land travel, but that will change as of Summer 2009. As of Summer 2009 you will need a passport for any land travel into Mexico and Canada.
If you live in Mexico then no.
If you are traveling from outside Mexico, all cities you travel to require a passport.
nope
Yes
No. New Mexico is part of the United States, so you don't need a passport. :)
No. A passport is sufficient to travel to Mexico. A birth certificate is not valid for international travel. If you are traveling by land or sea, then you can enter Mexico with a US passport card, "enhanced" drivers license or "enhanced" non-driver ID.
To Canada you can; to Mexico you can't.
If entering Mexico via airplane, yes.
Yes.
Yes you do
Yes, you do.