No you can't.
NO
Mexico US citizens can legally purchase guns from a gun dealer or from another individual. There are a few states that have restrictions, but most do not.
I would not recommend it, especially with the current situation going on in Mexico!
New Mexico's gun laws are pretty lenient. New Mexico does not require a hand gun to be licensed or registered.
since the gun was fired in the us, the crime would be under the jurisdiction of the us.
Nothing: the US took those territories by the means of war.
In order, Canada, US and Mexico.
No.
They are in order, Canada, US and Mexico.
in order China, Canada, Mexico, and Japan
I am assuming you are a US citizen correct? Well, the answer is yes, Mexico has unarmed all its citizens- that is why the police in Mexico is corrupt and all of the Mexican government is bought out by the Drug smugglers. You need to be a resident of Mexico with a "Grey Card" and have a permit to have a gun in your home, then you have to go though background checks and maybe you can have a bebe gun... lol! Peace man.
No.