Well done Oystein.Not a bad synopsis.
I believe that the original demolition plan for the building (as described) was in position from the date of construction. It's original purpose was simply to allow the building to be brought down cheaply in it's own footprint at the end of it's life.
The insurers would have insisted on a more immediate way to bring down the building such as secure access hatches at strategic structural points of the building .Here standard explosives could be inserted and plugged into a prewired electronic demolition system as required. The same thing as is said to be done with important bridges and the like. Then the building could be brought down under short notice in the event of an evolving threat of it toppling over..
I believe that the already existing thermitic demolition system was used in the destruction of the Towers on 9/11, probably with certain modifications.. The thermite was pumped in as I say, day or night, office workers or no office workers, and nothing to be seen.. The power-down of WTC2 for 36 hours the weekend before 9/11 may have been to add the final touches to the empty building.
Simple gravity would cause the liquid steel to drop straight down through the holes where the columns underneath had been. It would end it's journey in one or other of the cavities specially prepared below the lowers.The now glassy fireproofing would have shielded the heat signature and the fierce light. I Think the portland cement component of the fireproofing only went up as far as the 36th floor. Most of the still-standing columns were about that height I think.
http://www.youtube.com/watch?v=-dWBBEtA5bI&feature=related
At the 80th-odd floor there was a blockage causing some of the liquified steel coming from the floors above to break the fireproofing sheath and flow across the floor where some of it was recorded spilling from the window of the 81st floor.
http://www.youtube.com/watch?v=Tz8fvp7eDNE
The oxygen tanks are what I would likely do if I was a perp in this situation so I included that in my dialogue between conspirators.
In WTC7 the wireless detonators could be programmed to fire in any desired sequence at the push of a few buttons.
Leaving out your 'Thousands with Pentagon connection' really not that many fully briefed people at all would have to be involved in frontline operations.
I may have other things to add as we go along.
Readers should read the first page-and-a-bit of this thread to come up to speed on the debate. Link provided below.
http://www.internationalskeptics.com/forums/showthread.php?t=215696