How did you derive your claim of the building being impacted by flaming debris? The official story doesn't claim the debris were flaming, but rather that they impacted with electrical equipment and such in the building which started the fires, and I figure the official story is likely correct in that regard. Granted, the guys who rigged the buildings could have easily included some devises specifically to insure such fires started, but the chance of the demolition of the towers not starting fires in WTC7 is so slim that I doubt they bothered.
By the way, I doubt our government or any other was behind the attacks, and consider it far more likely that they were masterminded by some non-state entity which maintains operatives within our government and others.