I like the points idea.
Even if there's only one post today and it only gets one small vote, it will get over $3,000 due to this design.
After HF17, rewards will be given based on a 30-day running average price for every rshare. The situation in your example will become "if only one post in a month", which will be less likely to happen.
The idea of leaving some of the rewards pool 'unspent' if users do not use all of their voting power though is interesting.