Your point is valid, but what is bothering me is the parsing of "terrorist" - does someone have to be part of Al Queda or some other network to be a terrorist? The government has no problem calling McVeigh a terrorist, even though they claim he was part of a cabal of TWO. El Al is a significant target. The motive seems that an Egyptian wanted to kill Israelis. If that were to happen in Tel Aviv, there would be no question that it was a terrorist attack.
Interesting point. The government (esp. at the time) likes for us to believe he was right wing nutcase acting alone, and he is a terrorist - but this radical Islamic nutcase walks into an airport armed to the teeth bent on killing as many Jews as possible (fortunatley he's taken down before many more people were killed) and this is an isolated incident. Let's review the Websters definition of terror:
4 : violence committed by groups in order to intimidate a population or government into granting their demands
Is radical Islam not a group?
At least THREE. You left out the guy that was the state witness against him and Nicols. He was convicted but got less than ten years.
No Beckett's point is not valid and the reported actions of Atta and his crew do indeed have instances where they were fairly open in expressing their anti-American feelings, in insulting people, in being rude, and also where their actions were pretty weird -- like learning to fly a 747 but not how to land it.
While some few can live a double life easily, many are unable to all the time. Perhaps it is the term "sleeper agent" that is misleading. That implies years of formal training in spycraft, a formal selection and screening process, years of training in being a "sleeper". From all reports, Al Queada is much less formal, much less orgamized at that level of training.