The problem with the 9/11 conspiracy theories is they are conspiracy theories. Any nut job will make up anything to back their belief on a given situation no matter what the facts are. Examples are Pearl Harbor, Landing on the Moon, Crop Circles (disproved), flying saucers, aliens, JFK, etc.
I don't believe we have been told or shown everything about 9/11. Too many puzzle pieces still remain about 9/11. If it ever came true that it was something our Government was involved in or supported you would witness the total breakdown of our government and the US would fall into anarchy pretty fast which would be a very bad thing.
The two 9/11 conspiracy theories that could hold any water in my mind are-
The WTC buildings were brought down via controlled demolition
A cruise missle or other weapon hit the Pentagon
If these theoris are proven true we will fall into anarchy. Given that the Government will do everything possible to make sure it doesn't happen - People will disappear, recordings changed, facts changed - whatever it takes. End result we go on living life until it is forgotton about - what does it really matter for the next 200 years? What does it matter now almost 50 years later who killed JFK? We still know for a fact that true Islam is a threat to us and they are trying to overtake our country and piss on our values.
If they are not true then we go on living life as normal. And we still agree that Islam is a threat to us and Islam is trying to over take our country and piss on our values.
People spend their whole lives on stuff like this, and the end result is usually the same - they are logged in history as Losers which pretty much happens to anyone who opposes the Government and the people that control said Government. It's all about control.