These are all unnecessary, to various degrees. Compelling your fingerprint requires a warrant, which officers had in the linked case. The controversy is whether a search warrant of a property extends to compelling a fingerprint, not whether officers can go searching phones with abandon.
Specifically: - TSA officers aren't police officers. They can search you because you're entering an airport, but you're free to leave at any time (though they can detain you until police arrive, as any citizen can). - Within 100 miles of the border (not only the Mexican) officers can detain people momentarily or search vehicles to ascertain their citizenship. That's the only additional power they have, they can't search your phone (or even search your glove compartment) without probable cause. - When you're pulled over for a traffic stop, a search requires probable cause.
You didn't mention the one time you might think about doing this: going through customs, where your 4A rights are weaker and less certain. If you're interested in learning more, US vs Cotterman is a good jumping-off point.