That doesn't cover airline bookings that happened via travel agent or directly into the booking system. Many airline reservation systems pre-date the internet (SABRE, for example, came online in 1964), and much of the architecture driving the airline industry is archaic (which is one reason why a system outage can have such a massive impact on flights).
Nonsense. The movie Enemy of the State came out in 1998 and the NSA was involved in the production, though the agency was portrayed negatively, to its chagrin.
How about Canada to Central/South America? There are nonstop flights from Toronto/Vancouver to several cities. There are also flights from Canada to southern Europe that pass through the US. Even flights within Canada (Toronto to Vancouver) pass over the US. And routes from Canada to Asia fly over Alaska.
E.g. if they can get you for some silly "illegal landing" violation they will, if not they'll try to trump up some other charges.
> 13 years ago. A friend visited an airline, and had a set of cables pointed out to him: "That's the feed to the NSA".
13 years ago, that is 2004 noone would openly talk about the NSA, Room 641A was only exposed in 2006. I would also venture that in 2004 noone had or needed a direct feed to the NSA, the Internet would already do. In case you do not remember, how 2004 was, by 2000 you have Expedia, Travelocity, Priceline, Hotwire, Tripadvisor all launched. Edit: as comments below and the article itself points it out, the NSA would get your data from the GDS if it's there, what I mean here is that OP claims a dedicated line running to the NSA when it could have just used the Internet instead of a dedicated line to connect to your system. By 2004, the Internet was plenty established for that. That's all I meant.
> There are well known stories about planes making unscheduled landings in the US
This is, in fact, extremely rare. A flight which does not start or end in the USA rarely has the need to fly over it. Europe/Asia - Central America would and not much else -- and there are very few such direct flights, mostly only to Mexico City. Even a London-Bogota flight wouldn't.
> CBP opening the front doors, walking down the aisle, and pulling one guy off the plane.
While the previous event is merely rare this would be extraordinary and all over the news, even if not mainstream news. All the news I can remember about law enforcement boarding an emergency landed plane is about unruly passengers, not this Bond shit. So... source?