Yours are excellent ideas and obvious to anyone with a brain. However, you forget the drugs pouring I through our borders. The cost of the wall is nothing compared to doing nothing.
I watched that show Border Wars last night. It was astounding how many drugs come through the border in cars. The smugglers know every little hiding place on a car. The agents have to take wheels off to find it. No way they can catch all of them or it would take forever to get through the border.