Down voting will probably get added to memo protocol eventually. I think positive reinforcement leads to better communities though. What do you mean by paid public censoring?
Slashdot used to randomly award high karma users a few moderation votes occasionally that they could use to up or down vote. Since they were limited (had cost), you used them wisely.
You guys are real bad at thinking like propagandists. Being able to reorder another persons feed in any way is a massive invitation to forum sliding hoardes. Chronological or bust.
Ah that'd be cool, like creating your own algorithm so relevant stuff is at the top? I'm all about that. It'll be tough to tune it perfectly but could be useful for sure.
Remember, memo.cash is one client of the memo protocol on the blockchain. The protocol needs dislikes. How this or another client uses that info is up to the creators and users.