The big problem with thermite solution is that thermite is Very Bright while it is burning.
Because it is generating such high temperatures and energies, a massive release of light is unavoidable.
The Swiss Cheese metal is produced after the building collapses. To the untrained eye, and without a chemical analysis, it WOULD look like some sort of thermite had done it.
If it were thermite it would have to be set off well before impact or after the building collapses.
Not only is thermite very bright it produces a LOT of smoke. Once the planes tore through the skin of the building any burning thermite would be visible.
The whole building would have filled with smoke if the thermite was set off before the planes hit, this would have been a good thing, since they would be forced to evacuate.
The swiss cheese metal and George W. Bush's paranoia made it look like something like thermite was used.
Too much of Building 7 was destroyed (no evidence retained to be very useful). People setting fires all over the place inside the building could have brought it down. Without evidence a thorough and independent investigation that questions the principles (people involved) on why it may have been (conventionally) sabotaged to fail.
The Building was not a normal building, it was built around a transformer station.
It had some instability that knowledgeable people could have exploited when using fires to collapse the building. I would lean toward people setting fires in the building, but again the thermite would advertise itself.
