I can't bring myself to address the OP so I will comment on this post. The OP pretends he is torn between the video as presenting evidence of a missile or not. He seems to be searching for a preponderance of evidence to convince himself to believe one way or the other.
This reveals a trait that I have long noticed in extreme truther claims like this - not following their "logic" to the next step and beyond.
To believe the possibility that a missile was fired from the plane is to believe that this plane took off from somewhere loaded with at least one missile. If it was indeed passenger Flight 175, then the ground crew would have become part of the vast conspiracy as well as anyone within visual contact of this plane taking off, not to mention the crew of people who would have installed it underneath this passenger plane. You just don't have missiles lying around on a shelf. They are inventoried. So someone or more had to check this missile out of storage and someone would have trucked it to the location where it supposedly was installed. Step by step, the vast conspiracy grows larger as well as the likelihood that one participant may some day spill the beans. There are probably more steps and more participants to this scenario, but I think you get my drift. Why increase the chances of discovery?
OK - let's say the plane that hit the South Tower was a different plane, already outfitted with a missile. No plane takes off from anywhere without someone knowing it, so that crew of people are now involved in the conspiracy. But now you have the problem of making the real Flight 175 with all of its passengers disappear. The vast conspiracy is increasingly expanding. Now one would have to ponder if Flight 175 was "disappeared", did "they" do the same with the other 3 flights, and if not - why not? If so, again, the vast conspiracy grows even larger.
I'm stopping here before my head explodes. No missile can be seen in that video and to presume that there could have been one is ridiculous when you take that kind of reasoning to the next steps. The OP could have settled this question within himself without making a thread about it if he had just done some logical thinking.