I'm sorry, this one can't make it past the largest mesh size of the bullshit filter,and it would have never made it past the grand jury, much less the preliminary hearing.
As in any crime, we look first for means, motive, and opportumity.

Means:

Why bother, we know aircraft flew into the WTC buildings. Regardless of the claims made by the video that it was all staged, why would it be necessary to do so? The buildings would have been made uninhabitable and loss of life would have been enormous. It wouldn't have been unnecessary to blow up the buildings using demolition techniques, they would have been severely damaged and the blackened stumps would have had a lasting propaganda impact. It takes an enormous amount of preparation to demolish a building with controlled explosions, including exposing the main structural members by removing trim, drywall, finish, etc. How could you do this without everyone working there knowing about it weeks ahead of time.

Motive:

Not only would it have been unnecessary, it would have been unlikely, and downright stupid. Planning somethng like this without word leaking out by now would have been impossible, and could easily have backfired. It would have required hundreds of skilled workmen from a very small industry where everyone knows each other. Even if you assume an evil Bush Administration masterminded the plot to have an excuse to invade the middle east (the only possible alternative explanation, the implication it was a real estate scam is laughable), there would have much easier ways to do it. The autopilots of the aircraft could have been replaced by mechanical overrides that would have done the job without the need to engage in demolition techniques as well. The luggage and air freight could have been replaced with explosives, although large aircraft loaded with fuel would have made this all quite unnecessary. For that matter, an evil Bush administration could have planted small tactical nukes on the aircraft and easily could have blamed that on terrorists, or even Saddam himself.

Opportunity:

We know two aircraft were successful in their mission. A third (Pentagon) was only partially so. This would not have happened if it were a government plot. One aircraft failed in its mission altogether and was brought down in Pennsylvania by heroic passengers. Many passengers notified loved ones by cell phone of what was going on. So are we supposed to be expected to believe that this government plot still required middle eastern suicide terrorists to make it all work? And yet was frustrated by passengers? And then using timed demolition charges to finish the job? It just doesn't make sense from the git-go.

Summary

As for the rest of the presentation, I will not comment further because I am not a structural engineer, but I am a former professional propagandist, and I still pursue it as a hobby right here on the HZ, and I can tell a deliberate attempt to pass off a lie when I hear one: the breathless question, the incredulous tone, the deftly disguised sarcasm, the assembling of evidence which, although not necessarily wrong, is either inapplicable or inappropriate to the case in question. Then there are the accusations of cover ups and of witnesses being silenced and ignored. As far as the science is concerned, I do have some training in science and I see no smoking gun in the evidence he presented which could not have been explained by the official explanations. I would have to be a qualified structural engineer to properly evaluate the many Aha! claims Gage makes. So I see no reason to accept them as true on the surface. As for all those testifying experts he quotes, why should I trust them and not the official experts.

These buildings collapsed due to structural failures caused by both heat damage and the falling weight of the building itself provoking further failures. When structural members fail, they make loud noises. As masses of metal and stone move under the action of gravity they create shock and pressure waves. The heat generated by friction is enormous. The human bone fragments on top of the Deutsche Bank building would not have been propelled there by the small charges used in routine demolitions, but very well might have been due to the compression waves of air trying to vent out of collapsing floors. The only thing suspicious about this presentation is the fact that someone went to such an enormous effort to put it together.

As for the only truly valid point made in the video, that the building was designed to be aircrash proof and still collapsed, this is no suprise. Engineering predictions of events which can't be modeled are often incorrect. Are there unanswered questions? Of course there are! This was a major and unprecedented catastrophe, of course there are going to be unexpected results and unnaccounted-for facts. I sat through this entire video and I am convinced it is bullshit.

Post Script.

If you really wanted to destroy the WTC and you had unlimited resources to do so, why bother with a tricky and easily foiled controlled demolition that would have to be precisely coordinated with iffy aircraft collisions and unstable middle eastern terrorists? Why not just place sufficient explosives in the parking garage? That's how terrorists tried to take out the building earlier. You would have gotten away with it. And no one would have questioned you.