On solution #6: Yeah, it only works if the profiles really do cancel out. But I classified it as involving the decision rule because if your rule is simply to sum up the utilityXprobability of all the possibilities, it doesn’t matter if they are perfectly symmetric around 0, your sum will still be undefined.
Yep, solution #1 involves biting the bullet and rejecting regularity. It has problems, but maybe they are acceptable problems.
Solution #2 would be great if it works, but I don’t think it will—I regret pushing that to the appendix, sorry!
Thanks again for all the comments, btw!