DR Amy - I basically agree with your analysis of Election 2000, except that I believe the majority of ballots that had two votes contained votes for Gore and Buchanan, not Gore and Bush. And since the district was heavily Democratic-leaning, I think it is pretty safe to assume that had the ballot snafu not occurred, Gore would have won the district and therefore the election.
Had they held a re-vote, I think the turnout would have exceeded the November 4th turnout, because as you surmised, people would really feel like their vote might make a difference. But what a logistical nightmare.