Do you have any more details about Donald Rumsfeld's announcement of the missing trillions? It sounds like it was an announcement of defence equipment that couldn't be accounted for, probably over the timespan of several years. It is an awful lot of money but if the government was attempting a cover-up, would it not have been better to cause the destruction of WTC7 and parts of the Pentagon before Rumsfeld made the announcement. Then, the chances are that Rumsfeld wouldn't have had to make any announcement at all: everyone would have had other things on their mind. Even if he had had to have made the announcement, the day(s) after 9/11 would have been a very "good time to bury bad news".
You claim that one of the offices destroyed in the Pentagon was the one that would have been investigating the missing trillions: is that a guess or do you have evidence? I suspect that such an investigation wouldn't have been confined to a single office or offices. The missing cash/kit is probably spread over several campaigns (Iraq, Afghanistan, the various western Africa interventions, etc as well as homeland service).
The actual answers of where the missing trillions are, are very likely hidden in hundreds of thousands of accounting spreadsheets and equipment sign-out chits, and would need a large forensic accounting effort to uncover even some of them. This type of information doesn't usually exist in one place. It'll be strewn all over the entire US military infrastructure, from the Pentagon to Pearl Harbor, and operational HQs all over the world.
The video skirts round the issue of the different ways in which a fire can destroy a building. It only describes how buildings brought down by controlled demolitions appear.