I can see these points, but I think what you're missing is the "expectations" factor. Six months ago, no one expected Howard Dean to be anywhere near the position he's in now. In Iowa, Gephardt is ahead, but everyone would expect him to lead there comfortably, thanks to all of his union connections (that's another thing you missed - Dean's pickup of the AFSCME and SEIU endorsements is a huge, probably fatal, blow to Dick Gephardt). In short, Dean doesn't have to "win" Iowa in order to chalk it up as a victory - all he has to do is make a respectable showing.
New Hampshire - this was expected to be Kerry's prize, from which he would pick up the necessary momentum to at least make the "finals" of the nomination. Dean's got a double-digit lead on Kerry, and probably won't lose too much with his "pickup trucks with Confederate flags" comments - Democratic primary voters in NH are going to share the candidates' hatred and disgust for the South. If Kerry gets blown out in NH, his own backyard, what's he going to do anywhere else? He'll be cooked - the action then moves to South Carolina, and Kerry shares Dean's electability problem in the South.
No one in the world expects Dean to do very much in South Carolina, and he actually may have done himself a favor by shooting off at the mouth, in that he lowered the bar for what will constitute a "victory" in SC. Again, all he'll have to do is make a somewhat respectable showing. Eventually the primary action will move to other states where Dean will do much better.
In summary, I think the nomination is Dean's to lose.
The expectations have now changed. The six months ago things are history. Expectations for Dean are now sky high. A win for Gephardt or Kerry would be big now.
In Iowa, Gephardt is ahead, but everyone would expect him to lead there comfortably, thanks to all of his union connections (that's another thing you missed - Dean's pickup of the AFSCME and SEIU endorsements is a huge, probably fatal, blow to Dick Gephardt).
Those are service unions, very different from Gephardt's manufacturing etc. supporters. He didn't get 'em in '88 either. He's never been the leader for their endorsements. Big win for Dean, but not at Dick's expense.
In short, Dean doesn't have to "win" Iowa in order to chalk it up as a victory - all he has to do is make a respectable showing.
He needs top two in each to avoid a collapse. He can lose to Gephardt in Iowa, no big deal, but two second place finishes would be far from a victory.