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.