Did American invade Iraq without provocation?

Define "provocation." Specifically, describe for me an action Saddam could have taken that would have been sufficient in your eyes to warrant a massive military invasion and regime change. Details, please.

Related question: would the results of that action been a sufficient price for America to pay to avoid the charge of being "preemptive?"

Is America occupying Iraq after invading without provocation?

I'm not sure this question even has meaning. Does one have to be especially "provoked" to occupy a country you have invaded, or is it standard practice in warfare to invade a country and go home the next day?

Is resisting aggression self defense?

Yes. So what? As I tried to explain to you, the fighting we are seeing now is not from the Iraqi people as a whole "resisting aggression." I don't feel like repeating it. Short of drawing a picture, I don't know how else to put it.