OK, the idea here is to merge the Survivor idea with the football skills competition idea. Basically, we would play Survivor and all the challenges would be football-related. So, we'd start with 2 tribes, one with 4 players and one with 3. We'd have three team immunity challenges where the losing team would lose a member. This could be done at random as Matt suggested or maybe some other way - like a quick challenge. For example, we could set up a circle with cones and each tribe member has to throw a football and try to get it as close to the center as possible. Whichever tribe member misses by most is knocked out.
Then, once we get to four players, the tribes merge. At this point, we would have 2 successive individual immunity challenges where the winner gets immunity and the remaining players again have some way of being knocked out (random or quick challenge). This would leave the last 2 players for one final challenge (this final challenge would somehow involve the other 5 players) where the winner would be the Ultimate Survivor.
As for the setup, Matt and I would make the challenges up and we would coordinate the event. Challenges would be revealed one by one. To give you some idea of the types of challenges we could have, here are some ideas I've come up with (note that this does not necessarily mean they would be included in the actual event).
Team challenges:
Individual challenges:
I was thinking that maybe the players who get out could kind of referee some of the later events. However, what you say makes sense. In that case, we would work the players who are out into the following events in ways like those that you described:
For example, include each eliminated person into each future challenge. After the first person is eliminated, he becomes the automatic "blocker" in the thrower/blocker challenge. After the second person is eliminated, he also becomes an opposing force in the next challenge. And so on and so on until a champion is declared. Not only would such a system keep everyone involved throughout the whole event, but it would also give each challenge the same difficulty for each participant/team and allow the challenges to become progressively more difficult.