So the grievance thing somewhat sounds nice, but I'm not sure why it's used at the exclusion of the "Ignore" button. Also, I'm looking through the rules and the forums and not yet finding out what is and isn't a grievance. Now maybe it's the law student in me, but I'm slightly fearful of the creation of a term without a solid definition. It's sort of like "enemy combatant" or "pornography" in which we're supposed to know it when we see it. So I think a grievance FAQ needs to be added to the rules (or put on the page in which one can file grievances). But what needs to go on it? What is (and isn't) a grievance?
Missing 3 turns? Deadbeating? Missing turns and then getting the extra armies? Attacking someone for no clear strategic reason? Playing poorly on your team in a team game? Making you wait 18 hours when you thought you would be playing a speed game? Having played with one other player in many games that aren't team games?
There are plenty of things in CC that other people do that are frustrating and make you not want to play with them, but certainly not outside The Rules. Many of them (especially those related to missing turns) could be malicious, or could be legitimately excused.
Anyway, if you were writing the law for what is and isn't a grievance, what would you put?