Interesting stuff .. enjoy reading your thoughts Warbler BTW..
Couple of points here though..
With the way the American primary system is structured, it is virtually impossible to win (ie become the candidate for either major party) without either winning or doing well in Iowa or New Hampshire.. however, the definition of 'doing well' has a lot to do with (possibly more so than anything else) what is known in American politics as the "expectations game" (ie where a candidate can perform relatively poorly but still gain momentum, without doubt the single most critical factor in American presidential politics).. no point going into that though..
This is unlikely to be an issue for Edwards, however, as he is currently neck and neck with Clinton in Iowa (depends on which poll you look at), although he hasn't a hope in New Hampshire (although the almighy powers of "mojo" could of course change all of that)..
You mentioned the 'electability' factor as well.. this saved the day of course for John Kerry last election, but it didn't come into play until very near the caucus.. there is of course a very real possibility of this happening again, but certainly not this early.. as you say, this perhaps presents an opportunity for some of the more 'electable' nominees to become value bets..
Interesting to note as well the impact (sometimes damaging in the long run) that the primaries can have on certain candidates.. obviously in the primary season candidates only have to concern themselves with the needs of the voters of their own idealogical ilk (supposedly at least 
), thus serving to drive some candidates either wide left or right (party-dependent of course).. Edwards himself seems to be the primary example of that this time, as he has made a beeline for the wide left of late, as well as being particularly confrontational (with very little effectiveness I might add), in an attempt to barge his way into the invisible "top tier candidates"..
Lastly, Edwards (who is a complete and utter fraud as far as I'm concerned BTW) is far from a lock to win the south IMO.. I reckon that if the South Carolina primary were held today both Hilary and Obama would stuff him.. however, it is hard to emphasize enough the role of momentum in American politics and whoever comes out of Iowa and New Hampshire with that momentum is more than likely to sweep all before them..
And this isn't even touching upon the general election.. 
