Let me go down the list:
Your first argument is evidence of controlled explosives. You falsely claim that controlled explosives are the one and only way to produce these effects. The key word there was falsely. There are myriad other scenarios that can cause buildings to implode in on themselves, particularly tall towers, not the least of which is that when they're BUILT, they're designed to be prone to imploding in the event of a catastrophic natural disaster such as an earthquake, to minimize collateral damage.
Your second argument refers to the burning temperature of jet fuel versus the melting point of steel. It is an accurate theory were it to be applied in a controlled environment, i.e. open spaces and no other stimulus. However, the fires were contained (compare the temperature of a fire outside to the temperature of a fire, say, in a closet... the heat compounds itself). Now, having established that in an ELEVATOR SHAFT the fires would be more than well enough contained to dramatically increase their temperature, add to this that the heated steel was being subjected to other stressors such as the added weight of supporting the upper portion of the building after a considerable chunk of framework meant to share that burden was removed. The pressure and stress being applied would have further weakened the steel in it's already super-heated state.
As for the suspects, not all 16 were on the planes. You can hijack a plane with 2 or 3 people... hell, you can do it with 1 if you've got a good plan. The others were "accomplices" as you said yourself.
I've seen both Zeitgeist and Loose Change, and they're very convincing, but they're still conspiracy theories. I've yet to see a motive established that any reasonable person could believe would drive a president to attack his own nation. Keep in mind how people get IN to office... people with intentions such as those you describe don't run for office to accomplish them. People who run for office do so because they have ideals, because they want to serve their country and help to make it better. I haven't seen anything yet that would demonstrate how such a person could become so twisted along the way as to even think of attempting what you describe.
Then there are the Taliban, who openly claimed responsibility for the attack, and Al Qaeda who are their allies. Both are long-standing terrorist groups responsible for many other attacks against American interests for decades past, and who are well known for their hatred of the U.S. and for being large enough and well-funded enough to accomplish something like 9/11. Are you going to suggest that they, too, are all just puppets of the U.S. Government, created by them to provide an alliby? If you're going to go as far as to say that's the case, you may as well put on your tinfoil hat first.
You told us this is the "tip of the iceberg" and that we should "do the research ourselves" but it seems to me you yourself have done no such thing. You're regurgitating the works of conspiracy theorists who came before you, which would have obviously be intended to guide you to just this conclusion. I could be mistaken of course, but there hasn't been a single person I've met to date who believes this theory that has turned out to actually reached that conclusion by thinking for themselve, and I believe you're no different. I daresay you are yet another example of an American looking for an explanation of how something so terrible could have happened, and choosing the most controversial one simply because it's more exciting that way.
But I won't dismiss your argument so easily, because though much of it is circumstantial and easily doubted if you really do do your own research, it doesn't change the fact that depicting 9/11 as an inside job is an easy picture to paint. I remain open to the possibility, but I'm still highly skeptical that our own government was behind it.