Ok by the numbers:
"Nobody has told me how we are going to avoid MASSIVE political damage."

What would you call Massive political damage. I would say rather that you could make the argument that Bush's previous decisions have brought us to the point of "Massive political damage"- the current situation in the UN. But even though this could be characterized this way, it's not really that significant, unless you had dreams of the UN being a world govt. So the UN has shot itself in the foot. The US has spent huge amounts of time and treasure trying to make the UN a workable system and this might all go down the toliet. Is this what you mean by "Massive political damage". If this isn't what you are talking about, what is?

"Nobody has proven collaboration with terrorists."

That's your opinion. I think there is enough evidence of this connection, and there are good reasons to expect that this could be a growing threat.

"Nobody has demonstrated clear and present danger or immediate threat."

Terrorism won't have a "clear and present danger or immediate threat" if it was "clear" then steps could be taken to stop it. Terrorism operates by employing surprise. Though if you want some other types of examples of "clear and present danger or immediate threat" you have Saddam shooting at our aircraft in the no fly zone, and you have Saddam paying terrorists to strap on explosive and explode themselves in crowded areas. These have happened, are happening, and will continue to happen.

"Nobody has demonstrated why Iraq, given the current set of justifications, and WHY NOT about 6 other states first."

If the President had chosen any of these others, you could say he should have picked another one. I don't know of any other country which should be dealt with before Iraq. Iraq has been an unresolved issue for 12 years.
Probably the only, more significant problem in the Middle East region is Iran. Iran certainly has it's problems, but at the same time Iran *seems* to be making progress in terms with it's own population and it's foreign relationships.

"Nobody has shown me how we will keep unilateralism from being employed by the nations we have used international consensus to keep in check- namely China and Russia."

The problem is you don't understand what's keeping "China and Russia in check", the UN certainly wasn't a main factor. The problem is that the UN won't co-operate with the US. The US will take action whenever it perceives a risk to it's Security. The Middle East is a region with 2/3rds of known world oil reserves. Stablity in this region is important in terms of world security. Allowing a dicator who invades other countries in the region and who has proclaimed that it wants to dominant the region, is a concern in terms of security. The fact that this guy has WMD and is quite willing to use them, AND [rightly] perceives the US as a major obstacle to it's plan to control the region. AND after losing a war, and agreeing to give up WMD, then thwarting all effort to rid itself of WMD. All adds up to a threat to World and US security.