Happy New year @dan! My opinion is to have:
reputation separate from SP and it should be harder to gain and easier to loose?
Have random upvote periods (encrypted for 7 days) so that it's harder to coordinate attacks.
Proof-of-human® is also essential but how to do it? Sign/Hash/Encrypt all your fingersprints and ask randomly for one of those prints? A couple of modern phones have digital fingerprint readers...
Proof-of-human
Proof-of-ban-from-china. How to hide your person when goverment is coming?
Well, don't use your real name and use a VPN? Or Tor?