A few 9/11-anniversary questions

Why do a number of prominent progressives, some of whom have made careers out of questioning the U.S. government’s motives and methods, continue to vigorously defend the government’s findings around the events of 9/11?

World Trade Center building 7 was not hit by an airplane, yet it collapsed into it’s own footprint. I’ve read various attempts to explain this, but none of them make sense, not because they are too technical, but because they simply defy logic.

I’m certainly not an engineer, but I can understand the concept of the heat from the plane’s burning fuel weakening the metal supports in the Towers enough to cause a collapse. What I don’t understand is how hot liquid pouring through a building would weaken the metal beams at the same points around the circumference of the building in order to cause the buildings to fall straight down. Logic tells me that the intensity of the heat from the fuel would affect the metal beams at different areas up and down the building, which would cause the upper section of a tower to fall to one side or another, not straight down.

Why did Bush sit on his ass in a Florida classroom for seven minutes after being informed that America was under attack?