Media conventions have been cordially despised by fans ever since the days of ST:TOS for being ginormous goat ropes and money traps designed to quickly separate fans from their money by any and every means possible. The ones that are fan-run are somewhat less suspect than the ones run by for-profit outfits like CreationCons, but only somewhat. There's just too much money involved, for one thing, and because of the Five Geek Social Fallacies the necessary oversight to keep someone from busting the con budget wide open and tipping it into bankruptcy (or worse, looting the con for all the money they can steal) usually isn't in place until after the horses are loose and the barn is in flames.
Incorporating is only part of the answer. There needs to be an internal audit committee keeping a suspicious eye on the Treasurer, who in turn should be a paranoid tightfisted fuck who hates writing checks and demands receipts as soon as anything more expensive than a candy bar is bought with convention money. "Trust" should not be a word in his vocabulary. Maybe I'm being extreme here, but would you rather have someone like that in charge of your money with a couple of other senior staff looking over his shoulders, or would you rather get a call from the bank to inform you that the 150 kilobux you thought you had in the bank have gone missing?
I also think the timeline on the ConRunner.net site is ridiculously optimistic (18 months lead time to sign a hotel? YGBSM! Try two years!) but that's another kvetch for another post.