Related to voting part, I would like to consider cognitive aspects for more active and responsible participation.
In short, max witness voting should be decreased.

Theoretically numbers of witness vote do not have differences since one can split stakes. But according to Dunbar's theory, the first cognitive threshold (i.e. best friends) is 5 at max, and the second is 15, then 30. 30 max votes mean voter should use 3rd threshold to manage full witnes vote list, which is very burdensome. Many voters cannot manage it so voting power can become somewhat concentrated.
To as many people use their vote as possible, I think 5(1st threshold) is a good value. If we want to incenticivize some active voters, between 5 and 20 can be chosen, but I personally prefer lower than 10, which is slightly lower than 50% of 21.