Etiquette of the coopertition bridge

[Grim Tuesday]

This is one of the few questions that can not be answered by webcast, nor has anyone really spoken about it much on Chief Delphi.

What are the rules of etiquette surrounding the Coopertition bridge? How rude is it considered to reject a teams offer to balance? When are the offers made? Long before the matches? Right before them? During the match? How do these change based on the caliber of the teams involved? (ie, if you're the first seed, people may be more likely to choose to balance with your alliance rather than with one that the teams are both competing in the same bracket) Last but not least, are any teams making a "do-not-pick" list based upon choosing or not choosing to balance with yourself.

Thanks, and hopefully this should help set teams up for negotiations in Week 2!