> (I would go one step further and completely eliminate downvoting and thereby force everyone to think in the positive). That would go a long ways in the right direction with a minimum of negative fallout . . . I would think.

I like your thinking but I don't fully agree. There should be a way to deal with negative content like Plagiarism, Spam, promoting terrorism, encouraging crime (violating NAP) etc. 

>logarithmic/multiplier "diminishing returns" 

I agree to this on downvotes + a separate section for the community to see downvoted content/authors and decide to downvote if they too deem the content as negative. 

I love the fact that you want to keep things positive. I've extensively written about this here: https://steemit.com/steemit/@vimukthi/a-philosophical-and-economic-outlook-at-steemit-sbd-and-flagging-and-suggestions-for-a-better-future-based-on-positive