Adjust payouts to better reward minnows.
I've been saying this forever! :-) I hope it catches on one day. The problem with a lot of these ideas including minnows getting a weighted reward in their favor is that people who want to abuse the system can always open multiple accounts. I don't want to push for a system where we all need to give all our information to steemit but perhaps having an option to authenticate your account with KYC details and then authentication would give you some benefits and some others would be reserved for people with interaction with a wide variety of authenticated accounts (so even if you remain anonymous, you could still benefit if you had the trust of enough authenticated people. Benefits could include self voting to a certain extent (limited) and delegation of a high % of SP, and only 2 authenticated accounts would be able to upvote each other regularly etc. It could still leave people with the choice to remain anonymous while helping to cut out some of the abuse and allow some changes in the algorithms to actually work.
Yea, economies are tricky, and you don't want one corrective action to just cause people to abuse a different system. On the other hand, just because abuse will always occur in some form doesn't mean we shouldn't take small, gentle and careful action to reduce that abuse in some way.
The problem with lots of multiple but non-contributing accounts is that they are ultimately just shrinking the value of a vote. In the same way that bidbots are taking the opposite approach of making 1 vote worth an extremely over-valued amount.
Some of your ideas may be worth exploring to produce a goldilocks, 'just-right', vote value.