When I say relevent I just mean that if someone wants to cover something up is it usually because it's irrelevent?
Here's the problem with your logic:
"If evidence A is covered up, then it will be left out of report B."
"Evidence A was left out of report B."
So far, so good. However, you go from that to this:
"If evidence A is left out of report B, then evidence A is being covered up."
The conclusion doesn't follow from the premise.
I know you were just asking rhetorical questions, but here are some non-rhetorical answers:
I think the fact that they had extra airline tickets touches on a couple of possible things other then maybe some of them might not have been fully in on what was going on. Did they all have to know the plan was to crash the plane?
I think so. The "muscle" hijackers were trained in close-quarter fighting. How do you think they would react when they found out they were being sacrificed? Wouldn't that throw a monkey wrench into the plan?
And just how much money did these guys have and where exactly did it all come from?
How is it possible that you don't know this? They were funded by Al Qaeda.
They flew first class didn't most of them? Did they all have multiple flights booked? Were they all first-class? Did even one of them have a job?
The ones that needed quick access to the cockpit flew first class. The hijackers needed to be distributed throughout the plane so that they could a) pacify the entire complement of passengers, and b) not raise suspicion as to why so many Middle Easterners were traveling together.