We have an impossible collapse scenario in which the upper block of the North Tower descends at virtual freefall speed right through the intact core structure below it. Assuming you're not pretending to not understand what "smashed" means in that context, I'll help you out. It means breaking every connection of every cross-bracing to every core column, and then pushing the core structure of columns down through itself at virtual freefall speed right from the beginning of the collapse. And assuming that you really don't understand how such an acceleration--40 feet shy of freefall in the first 360 feet of descent--of collapse required more energy than was present in the closed system of the Tower's potential energy, I don't think I'll help you out with that because there's no way that you don't understand the ridiculousness of that proposition. But that doesn't mean I wouldn't be entertained by your attempt to explain it.
And concerning that incredible dust cloud which could only have come from the closed system within the Tower, I didn't mention pyroclastic clouds, so why are you mentioning it? However, that cloud of dust expanded at a rate which, like the upper block dropping through the core structure below it at virtually freefall speed, cannot be explained by gravity alone. Here, have another look:
http://niftythings.org/usattack/wtc_collapse/P7300435.jpg
So far, we have you standing here pointing to office furnishings, ceiling tiles, and gypsum board to explain it. If I were you, I would opt for the inclusion of concrete dust because without it, you're left with ceiling tiles and gypsum board. You might just as well, since your pics don't show six thousand tons of concrete.
And of course nothing was laterally ejected. Anyone can see that! All they have to do is look, right?
9-11 Research: South Tower Collapse
. . . Riiight.
Now, back to where we started. Explain how the energy required to pulverize most of the concrete and everything in the building below the impact zone, plus "smash" the steel core, and the energy required to produce the explosive lateral ejections--
as seen in photos of the collapses--still allowed for enough reserve energy to allow for a virtual freefall descent through the course of most resistance.
Go.