"Inside job" seems to have multiple meanings. If it means foreknowledge by at least one agency and other foreign agencies, and failure to decisively react by those with authorization in the U.S. government, then yes that is all indisputable and on record. But there is still zero compelling proof that 9/11 was literally planned and executed by gov't insiders.

Be wary of the elaborate and non falsifiable speculations when it comes to this. For example, it's religious dogma here to deny an airliner hit the Pentagon. With this belief you kneecap the severity of documented examples of government complicity and complacency. In this case, "no plane hit the Pentagon" gives Cheney a big fat pass. He could never be held legally liable, even in theory, for refusing TWICE to give a shoot down order, if the plane was non existent.

Be wary of official narratives as well as many of the alternatives. They all tend to play on emotions over logic IMHO.