That's possible, but I couldn't cover all scenarios. One might have been that they would clog up multiple airport runways, thus diverting more and more planes to more and more airports, with the intent of clogging up as much as possible and creating an impossible situation for the air controllers. They may have created so much fear that airplanes may have run out of fuel or may have been forced to ditch, thus dramatically driving up casualties. One thing I didn't take into account was that it would have been quickly learned that all the planes were coming from one airport in England, thus any flights from there would have been the most suspect, and they would have been diverted to more isolated runways if possible.
Any one of your scenarios makes far more sense than what we were being fed at the time. It was ridiculous to think the jihadists would have wasted their efforts over the water. I chalked those reports up to a combination of official panic control and vapid journalism.
Regardless of what the precise scenario was to be, the given is that muslim terrorists intended the carnage to be massive. And the U.S. was the target.