It depends on your home country, but most often than not, you need to visit your local travel agency for guidance.
If you live in Mexico then no.
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 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.