1. No, unless it is an Anniversary, you live locally and don't have to travel far so those expenses are out of the equation. Don't get me wrong, I loved the race this year, and really wanted to do it this year. But, I am not going to pay the registration for a 5K that is approaching nearly the same amount as a Half Marathon at Disney, that doesn't have the Expo, and start that late at night. If it is your first 5K and the cost doesn't bother you, go for it. It is fun.
2. I thought the After Party was worth it if you love Animal Kingdom. I do, and love Expedition Everest and enjoyed riding that over and over and over. The selection of food wasn't great, but everyone was gone by about 12:30 a.m., so for the next hour and a half, we had no wait on any rides.
3. Personally, I would recommend doing this as a team (whether you sign up as one doesn't matter either way), simply for the scavenger hunt. It is so nice to be able to work with another person on solving the clues. Although people do help you, I think most people were a bit too competitive, mainly because they were tired and wanted to enjoy the party. I would imagine that will remain the same next year.
I do love the medal, but it is the same as last year, and I can't donate it to Medals for Mettle so I am not going to waste my money traveling for that. I will wait until the 10th Anniversary if it actually gets to that point.