The questions which would end the conspiracy is the other 80 odd videos the FBI hold which have never been released. There is no reason for them to be held, if they don't show anything as in the plane hitting the building, then release them, they don't contain evidence but if they do show a plane hitting the building, then it would pretty much be a done deal for the offical story.
Unless releasing the FBI believe that by releasing the footage, it would embolden the terrorists. lol
I certainly hope not that is not a reason.
While you're there, also take a look at this, which I should have linked for Nuke_em a couple of days ago.
There doesn't appear to be anything sinister regarding the lack of clear video at the Pentagon. We'd need blind luck to have really good video of the event. How many good videos do we have of Flight 11 hitting the WTC? There is only one that I'm aware of off the top of my head; and it was captured by blind luck. How many of Flight 93? Sure, we have plenty of Flight 175, but the only reason we have several videos of Flight 175 is because so many people were recording the damage from Flight 11.
Regardless, an aircraft did indeed hit the Pentagon. The evidence for this is overwhelming. Was it Flight 77? In my opinion, yes. I haven't seen any plausible reason to doubt that Flight 77 crashed into the Pentagon.