I don't think 9/11 Truth should limit its concerns to whether or not Bin Laden did it. Yes, his guilt or innocence is important. But a truly transparent investigation has the potential to unearth a number of things: state sponsorship in the plot; a variety of tagential crimes by integral individuals (eg. Sibel Edmonds' revelations); incompetence; and others.

That is, I think the reason the scope of such inquiries is ALWAYS limited is because there is a whole class of criminals at the top of the food chain, and they all understand that freeranging investigations are bad for their collective power.

I don't think Kean and Hamilton KNEW they were engineering a coverup. I think they were handcuffed in certain ways (limited funds, limited access, limited time), and they probably understood innately that they should not do a real investigation. I don't think anyone had to tell them.