From your 'about the squibs' post further above...
You say they were well ahead of the collapsing structure. I agree, but probably not as far ahead as it may seem. Just because we saw the outer walls blow out at one level, doesn't mean something wasn't going on inside ahead of that action... there was mountains of mangled steel and concrete churning down through those towers like a mega meat grinder. There is nothing to compare it to. Massive, and certainly enough to compress the air violently. Those squibs could have been a result of the collapse.
Look at the squib at about 5:55 http://www.youtube.com/watch?v=_4dpBzDm5MU
With so much of the building material having ejected OUTWARD, are you really suggesting that "mountains of mangled steel and concrete" had dropped through the lower floors of resistance SO fast inside the building for that squib to appear THAT FAR BELOW the visible area of collapse outside at that same time?
...and that it could've produced the super heat for the pyroclastic flow, as you've suggested elsewhere in this thread?
Sorry, but that doesn't ring of fact and common sense to me. That sounds like you're making stuff up as you're going along.