I have no problems with stopping sign ups, but going from total organization to utter chaos could prove problematic. Couldn't we open a thread, say, one hour previous to the tournament where people signed up? This way people would be much less likely to sign up, then not make it. (you should know what you're doing an hour ahead). This would solve the problem of handing out prizes through the forum, and it would keep the tournament organized, not on a very easily disrupted system.
However, i'm really not a fan of this 1-game round thing. I think that, if we use this one-hour previous sign up system, then any reserves at that point (or those who sign up after 32 have already signed up) would have to go through this round. I'm not sure if it would already work like that, but so many good decks can lose one game on a bad draw.
note: with this thread, you wouldn't have to show a list of all names and edit them, you would just use the thread to get forum names / ign and to organize brackets.