Isn't the Yellow Card for a failed challenge a bit harsh? If you only get one challenge in the first place (and in the case of the finals, you can loose a time out) isn't that enough to deter people from overusing the system?
I think the likelihood of even having a situation where a ref missed a point, the team notices it, the missed point makes a difference in the match, AND the team is confident enough to challenge it are extremely unlikely, whats the point of having a system in place if it only gets used in maybe 1 match?
Like GaryVoshol said though, it is your game and your rules.
Regardless, this is sure to be a very exciting event!
