Impenetrable.
Two fences, 12feet tall laced with razor wire up and down. Separated but 30ft and a two lane road between them with vehicle stations every five miles.
Cameras and sonic sensors for underground activity. Armed guard towers with orders to shoot every 500yds or so. At least 1 Vehicle moving in each 5 mile section at all times and a "Special Response" force every 200-300 miles with a platoon of Marines in helicopters.
Kill any and everything that tries to cross it, every time.
Then severely prosecute every business that is found to have hired an illegal. Take everything they have and put them in jail. If anyone gets pulled over, or otherwise raises the suspicion of LEO anywhere, ask to see their identity...and if not legal, turn them over to the Feds. The Feds must then put them to work maintaining the wall for 1 full year before deporting them. In every case.
Federal law banning ALL transfer payments from the Feds to any other govt entity that offers any benefit/payment to anyone who cannot prove their legal residency.
Amend the 14th Amendment.
Then, institute a "Guest Worker" program that allows folks into the US, with proper ID, for a period not to exceed 1 year to work...if they have a contract. Give those folks full driving rights etc. After 1 year they MUST return to their home country for a period not less than 6 months...after which they can reapply in "preferred status".
The US Military should take all volunteers who are proficient in English and can pass all tests/security screens. Full pay and benefits for the duration of their active service...and after 12 years of Honorable Services, eligible to apply for citizenship in "Preferred Status".
Anyone who can deposit $1million in a US bank can stay under "escrow" as long as they are not a criminal. They would be allowed 10%/yr for investment and living expenses after deposit. After 10yrs, they are free to apply in non-preferred status.
Now that's what I call a damn moderate approach.
You have some very valid points. But, a couple things seem to be missing from your ‘plan’, IMHO.
Number one - as long as we keep giving freebies to illegals, they will find a way in. It is their dream to get out of the poverty they are living in. Come to the USA, and get free food, free education, free medical care for the whole family, subsidized housing and get a job that ‘the Americans refuse’.
A fence like you described will only accelerate tunnel construction and higher ladders and wire cutters selling out in Mexico.
Allow criminal aliens the honor of serving in our military?
NEVER!