I heard of Alec Station and Michael Scheuer and Imperial Hubris when I first came to 9/11 skepticism.
Thermite has been shown by scientific test to be effective in disrupting steel structures. Nano-thermite has not.
Thermite was used in 1935 to bring down two 600-foot steel towers in Chicago. These were not buildings, but were towers for some kind of a cableway ride.
According to NIST there were about 18,000 civilians in the towers when the 9/11 attacks occurred. 15,000 of them were under the impact zones, and all but about 100 of the civilians were successfully evacuated before the towers fell.
Many of these 100 were trapped in elevators that had recently been fitted with security interlocks that prevented elevator passengers from pulling open the doors. These interlocks were part of a nine-month elevator renovation project undertaken by ACE Elevator. The morning of 9/11, over 80 ACE mechanics gathered in the WTC lobby. Even though they knew that people upstairs were surely trapped by the interlocks they had installed, they left the scene. USAToday ran a two-part article on the subject.
The death statistics give the lie to William Rodriguez's claim that his "Key of Hope" saved hundreds of lives. If Willie had saved hundreds of office workers on the lower 40 floors of WTC1, then hundreds more should have been killed in WTC2 and on the middle floors of WTC1 that Willie did not reach. Willie's story depends on the claim that an internal collapse of 22 stories in WTC1 from 65 to 43 made his heroic climb up the stairs "opening doors and letting people out" unsustainable. Such a collapse should have killed many hundreds of people. It didn't happen.
The timing of the attacks was the controlling factor in the survival of 99.4% of the civilians under the impact zone. During normal office hours, the population of the WTC was 50,000--not 18,000. In the 1993 bombing, it took FOUR HOURS to get everybody down the stairs. Had the 9/11 attacks taken place on a fully-populated building, 20,000 or 30,000 people might have died. Had relatively simple measures been taken to obstruct the evacuation--such as tossing office furniture in the stairwells, attacking evacuees with table legs or samuriai swords or guns, or simply mixing ammonia and chlorine to make poison gas--the death toll could have been multiplied.
Thus the suspicion that the attacks were designed to minimize, not maximize, the deaths involved is greatly justified. How does al Qaeda benefit from minimizing casualties? If 30,000 people had died instead of 3,000 we would have had 40 Jersey Widows instead of 4, and that critical mass could have had a multiplier effect.
If the op was designed (such that not only was intel incompetent, but the terrorists were too) so that casualties were minimized, then we have to suspect that the destruction of the WTC might have been far more complicated than a matter of US intel looking the other way while a bunch of Saudi crazies flew jets into the towers.