The USGS thermal imaging detected temperatures up to ~1400F. Easily explained by the long-lasting debris fires, and hot enough to melt lead from UPS systems, or to keep fuselage and building aluminum molten. Simply put, nanothermite and other explosives wouldn’t produce pools of molten metal, and no incendiary known to mankind stays hot for more than a few minutes.
No, it is not so easily explained by long-lasting debris fires, because debris and rubble sat on top of it, smothered it, and made it difficult for air/oxygen to fuel such fires, particularly when the fire department began dumping water on it as well.
Moreover, you should Google what temperatures a debris fire, or an office fire, or even a jet fueled fire can reach, thereby further shooting down your explanation. Mr. Limey can help you on this, because he was recently given a tutorial on this on another of Mr. McKee's articles.
Your statements about nanothermite and other explosives not producing pools of molten metal are only half true. The half that is false is that those mechanisms could indeed produce pools of molten metal; the half that is true is that those mechanisms could not maintain those pools of molten metal over time.
No incendiary known to mankind stays hot for more than a few minutes.
This is (probably) true.
Now if you really want an Occam Razor easy explanation for the detected temperatures up to ~1400F, try multiple milli-nukes (as is 1/1000th the nukes you are envisioning). Unspent and fizzling left-over nuclear material from companion fracticided milli-nukes can easily explain the recorded temperatures, their duration, the methods employed in the clean-up, the high security of the area, the suppression of photos & images, the shipping off of materials for recycling, the song-and-dance dog-and-pony show of various alphabet soup govt agencies to control the reports, control the message, control the propaganda...
Señor El Once