Second of all, if and when we do invade Iran, we could go though Afghanistan, as The Redneck pointed out. Or, we could stage a bombardment in Kuwait, then march a bit through Iraq on the way there. Or, depending on the support we have from other countries surrounding Iran, we could find another country to launch attacks out of. Iraq is not an extremely strategic location, unless we're planning to invade and take over the entire Middle East--which, though such a ridiculous notion is believed by some, isn't practical or logical in the least bit. In short, whatever we need to do, we can do without Iraq.
Iraq's a big place, it can be used as a good staging ground for a lot of troops, especially if they want to pincer Iran. I stand by my comment.

Last, but certainly not least... We did not "accidentally" blow things up. When you have missiles that can find and go through windows, it's hard to miss. There's certain infrastructure that needs to be taken out of commission for a short time, but is then rebuilt, and at this point more people in Iraq have simple things like electricity, running water, sewers, and phones than any point in the last thirty years.
No, I've a firsthand source (which makes me secondhand I guess) that was giving out reparations. We HAVE blown up stuff accidentally, cars, buildings, what have you. We ARE paying that back. Also, my sources tell me that they are not by any means a third world country, they have had electricity, running water, sewer, phones, and the internet long before we came there. Again, I stand by my comment.