Now you're squarely on my turf. I teach people how to fly.
Let's take my favorite first, point number 23. There are two very easy ways to do this, especially on a day that pilots call "clear and a million", as September 11, 2001 was. One is to take a plotter, figure out the true course between Boston and the tip of Manhattan, take into account the magnetic variation and winds aloft (that last pretty negligible at 500+knots) and aim the plane that way (magnetic course works out to 250 degrees, btw). Or two, follow the Eastern Seaboard to the southwest. Eventually, New York City, with it's distinctive skyline, will appear in the window. It's not hard. In fact, it's a basic skill taught to all pilots at the very beginning of their training. The whole "you need ATC" to navigate comes from instrument flight rules traffic separation, NOT "we have to hold your hand from beginning to end." In fact, in IMC (Instrument Meteorological Conditions - you can't see out the window), pilots can and do navigate without ATC help - they're basically cleared to go where there going on a specific route and altitude. If no traffic conflicts exist, ATC pretty much doesn't even talk to you. Not that the last point is that relevant to the conversation, other than to illustrate how fatuous your point is.
Now let's take the next point in my mind, number 22. If you're merely trying to hit a large object with an airplane, it's pretty damned easy. Obviously, I've never done it myself, but I can pass directly over a selected point on the ground at a specific altitude anytime I wish. Not hard at all. In fact, it relates to my answer to point number 23 - it's a basic skill we teach (mainly so we don't run into things!).
Both of which demolish point 24. Again, running any airplane, regardless of type, into a structure isn't terribly difficult. Some other things, such as putting the main gear down precisely on the thousand-foot marker on a runway, that takes training, practice, and skill. But to hit a building? To quote Peter Sellers' character of Dr. Strangelove: "It only takes the will to do so!"
Four planes, 19 terrorists, three buildings, and one thwarted attempt, and thousands of innocents died. That's what happened.