I saw that video a few months ago... he makes some good points but ultimately you have to look at:
1. The guy that makes this video never states his actual credability as to what makes him qualified to make the claims that he makes...
2. Some of the shots that he shows are of such poor quality that you can't base any claims off of such poor evidence...
3. He doesn't bother trying to explain how hard it would be to hide multiple devices in a skyscraper... The Towers collapsed because the heat stress on the concrete... NOT the steel reinforcements... In a steel reinforced structure not all the weight is held up by steel. Concrete takes a portion of the load as to make the building more stable in normal conditions. The concrete was weakened by the heat which caused the concrete to fail... which in turn caused the steel to fail... Once the buildings became unstable the building fell inward weakening the structure below it and causing the seemingly controlled implosion of the towers... The bursts you see coming out of the Towers as they fall are explosions from air pressure and other debris leaving the building as the floors collapse on themselves... When you take a massive space and collapse it within in a few seconds the air is going to escape in a violent manner... appearing like explosions... it's pretty basic fluid dynamics... This claim wasn't very well backed up at all in his "conspiracy theory".
Why would the US do this? They wouldn't... The real reason why the video was confiscated from the gas station was mostly because the tape could have possibly been used as a guide to better show where to hit the Pentagon if it were attacked again... The tape was declared a threat to National Security and not released to the Public.
The guy makes some good points... but all in all it's just a bunch of BS that some dude that has no idea about any fundamentals of science (physics, metallurgy, or fluid dynamics) is making up to try and stir some feathers...