5. Require a passenger's license
Eliminate the clueless clods who are to blame for every bottle-neck and blunder in the first place -- require travelers to pass a short online test to demonstrate a certain level of competency and awareness before they can purchase a ticket. Cover how to go through security, how to stow your rollerbag in the overhead bin (hint: NOT sideways!), etc, etc. If you've never flown, there'd be a 101 you could study beforehand. Elitist? Absolutely. But the license would be free, and think about how much smoother air travel would go.