The death penalty for 2 kilos? Maybe, if these individuals are repeat offenders.That's debatable.
The death penalty for someone caught with a couple of bales? No question.
The guy that's unloading tractor-trailers with a forklift? Dead man walking.
Let's just say, for argument's sake, that your suggestions were actually implemented and America is now a police state with militarized borders and death penalties for drug dealers. I sincerely suggest that you stay on good terms with all your neighbors: if one of your neighbors crosses you for any reason just smile and say "That's OK". Because if you pi$$ off your neighbor too much, all he'd have to do is denounce you to the local narcs by reporting "suspicious activity" at your place. Then, away to the local station, endure some torture, be tried in front of a kangaroo court, and off to the executioner (or at least, a long stay in a forced-labor camp).
BTW, this scenario has been played out in the past many times. You can read about the times and places at length in Alexander Solzhenitzyn's "Gulag Archipelago". It's a very telling portent of what life in America would be like if we ever fought the "real" War on Drugs that you and many like you desire.
How long do you think the public will stomach little Johnny down the street getting executed for drug smuggling, considering we can hardly execute murderers in this country?