It is not a "trick". It demonstrates a simple physical principal, which it would appear you do not understand.
As you have stated greater than FFA "is not possible", the reason I have provided you with the simple example of greater than freefall motion is to help you understand
why over-g descent is physically possible, and requires no force not already present in even the simplest of physical systems.
The end of the stick falls faster than FFA
Why does it "fall faster than FFA" ?
but it requires one end be fixed
Neither end is fixed. The only effective restriction on movement of the ruler is that, in the example shown, the left end of the ruler is constrained from moving to the left, thus creating a "pivot". Hint.
In WTC 7, that would require explosives to remove all support from the exterior wall like the hand removing the supporting stick.
A hand in one instance, but explosives only in the other !?
Can you think of no other action or process which would reduce resistance ? Explosives or hand of god only ?
You can't attain FFA, much less greater than FFA, if the exterior wall is providing resistance.
Incorrect. You can achieve over-g of a point on the building if the downward force exceeds "g" for that point. That does not require the resistance to be zero. You were shown a diagram earlier which, regardless of your position, you must accept nullifies your statement above.
You can achieve FFA, and greater than FFA, even if the exterior wall is providing resistance.
Again, regardless of your position, or whether you are prepared to accept such as the real-world cause of momentary over-g descent of the NW corner, you
must stop making such silly statements. It is basic physics. You must change your stance. You have no choice. If you do not, you will simply receive ridicule from others here.
"a free fall time would be an object that has no structural components below it"
Again, no. Take the blinkers off.
First, understand... The end of the ruler exceeds FFA.
Why ?