The passport thing was no longer the case when I went there in 2016ish. It used to be you could go about 15 miles into Mexico without a passport but when I last went in 2016, you had to have one just to cross in to Mexico, and they were inspecting the heck out of it, and visa was required to go more than a certain distance or stay. A lot of poor Americans live south of the border in San Diego area because it's all they can afford. Mexico was pissed at Trump and changed the rules.
I like your last point on the tax thing, that's so BS the way that money isn't equal per student. It should be state wide equal property tax and state-wide equal per student.