For me best way would be to use the Steem inc stake delegation to counter spam/etc.

To remove the free downvotes means that many user don't want use their votepower for downvotes.

F.E. to announce child pornografy (as one example) should be honored and not punished (by loosing your votepower).

How many people would not go to police and announce their some crime if they would know that they had to pay a fee to the police for this ?