This is a similar solution to the web of trust solution I suggested a long time ago, but it generally just came back with responses like it will fragment the community and it will be too complicated for people to understand (it can be done transparently so I didn't understand that argument).
The one thing I want to point out here though, is that every time you create user moderation you necessarily will create a fragmented community with a large enough userbase. The existing moderation will create a fragmented userbase if there are enough users. Since the relevant features being discussed are related to following users, the proof can be seen just by visiting Twitter.
I personally think that if Hubski were to hit the mainstream one day (which it will eventually if it continues to function and the server bills continue to get paid, another real issue to discuss), a mass influx of users will just completely destroy the existing community as it is currently laid out. Voat hit their massive influx of users and all of the existing users just left because the trolls took over. Yes, they use a different system of moderation, a centralized one that could theoretically do better at filtering 100,000 trolls at once versus every user needing to deal with 100,000 trolls at once, and it failed. I'm not sure why everyone has implicit trust in the Hubski user moderation system if the influx Hubski has always received has been relatively small in comparison.
Mass influx of users just happens and is a natural disaster you have to be prepared for. It happened to Slashdot, 4chan, digg, reddit, and Voat. Those are just the ones that I personally am aware of. It will happen to Hubski, it's just a matter of when.
It's like the levee system in New Orleans. "It's worked so far, so why fix it?", then Hurricane Katrina hits and "nobody could have seen that coming!". Well, yes there were a lot of people warning about a hurricane that size threatening the levee system one day, it just fell on deaf ears.