You have highlighted some common dilemmas which we are collectively facing right now
Sometimes some posts receive below par engagement but still the authors invoke 3rd party upvote and reward their own posts and actually same category of people claim that reward pool is limited that we should utilize it more precisely (which I do agree with). Sometimes people make fishy accounts beneficiary of their posts which were originally supposed to redistribute rewards. One example do came into my mind is 'Steem Fantasy Premier League'.
I must admit you have made some great points.