If upvotes get curation rewards then maybe downvotes can get curation charges :) This disincentivises overuse of this, and shifts its use more towards negating clique-voting.

Yes, and invert the sense of the scaling of the share of the curation charges. The most accurate downvotes get charged the least.

I am not really up for making a post about this, I think that the curves for reward distribution become irrelevant when Steem's value goes up instead of down. Which may mean @abit's idea of a flat distribution may be superior, in the sense that it reduces complexity, which lowers administrative cost, leaving more for rewards. We just have to have a Steem asset that tends towards being deflationary, rather than as it is now, distinctly inflationary.