"Steemit is a permissionless system"
I disagree. You need the permission (or backing) of SP owning curators to enter the ecosystem for free, or you need to buy your way in through the STEEM token, of which someone has to decide to sell to you and at what price. The former becomes even more true if you want to make anything more than pennies- you need a large amount of "permission" "(or backing) from SP owning curators to make anything more than chump change. All cryptocurrencies are permission based in one way or another, "permissionless" is a technobabble buzz word.
"CAs aren't to be trusted by default either."
Did you even read the TL;DR? That is why shareholders vote for which CAs' certificates are weighted higher. You don't have to send your identity information to a CA that you don't trust if you don't want to. Maybe I need to make this clearer in the proposal, but you will still receive SP/SD even if you don't verify your identity. However, I am proposing that you receive a bonus in the the curation calculations if you do, so everyone has incentive to verify but does not have to if they don't want to.