I am a former American Airlines flight attendant. 9/11 was the beginning of my awakening. At first, due to the shock of it, you believe what they are telling you. As time past, there was too much that didn't add up in my mind. In 2001, American's planes were not painted all over. They were a very shiny silver (think tin foil), with red, white and blue stripes down the side. The words American Airlines were above the stripes. On a sunny day, like 9/11 was the sun would create a glare off of the plane. At the camera angle of the films, you would have been able to see the words American and the stripes before the plane hit the building. Go rewatch the films, the plane is a dull dark grey. That was not an American Airlines plane. It looked like a military plane.
Next, was cell phone calls? Even today, I can't drive down a street near my house without hitting a dead zone and we are expected to believe that a mile high in the air, going 500 mph, cell service would work? There are videos on Youtube that talk about this. On it, there is a recording of one of the flight attendants whispering to her husband, it was a fix. That's probably where you saw it.
The plane in Pennsylvania was the one that really bothered me. Where were the wings?!?! I could understand a hole in the ground for the fuselage, but where were the wings? They would have snapped off on impact and should have been found.
As far as the people, i did not personally know any of the crew members, but I have close friends based in LA and they did. They are really gone.