Thoughts on the EC:
If every team`s interest is only winning (not caring about their position in case they don`t), then the only thing that matters is the point difference towards the first place. If a team alone targets the first place for 15 points, this point difference remains the same, unless the difference to the second place is less than 15, so the team's main goal is not hurt if they are the only ones using the EC, though they may hurt their standings. If more than one team does it, then they are furthering their goals.
The only thing that needs to be considered is backstabbing, but then again there could be retaliation in the votes (as people don't vote 100% objectively).
EDIT: Is the wager/challenge counter right? Isn't it always 3 days before the main deadline?