1. Its a possible rights issue. I'm going to assume that ESPN had the US rights to the World Cup so therefore no issue doing pretty much whatever they wanted to in WDW. The rights to the Super Bowl are owned by NBC this year so WDW would most likely have to negotiate something with them to have any venue outside of the ESPN club which has its own agreement to show the game most likely with the NFL.
The last time Pittsburgh played in the SB the University of Pittsburgh wanted to show it on a big outdoor screen. It was all setup but canceled at the last minute due to rights.
The NFL is probably more protective of the Super Bowl than even Disney with Mickey Mouse. Ever notice how many ads you see these days talking about "The Big Game".
2. I think some NASCAR fans would disagree.