Who identifies what a person is? Is there an age restriction? How do you know each person actually controls the keys? I support many members of my family by helping them have a steem account. They are real people but I will be voting for many of them in votes like this.
A man with 4 children could stop any proposal/circle, even without any SP. In fact if I understand your proposal, that same man could stop every working circle.
Thank you for asking. Sorry, this is a misunderstanding. Only the whole community of active Steemians could stop a working circle by their vote, not a single group of five Steemians. Five can only get the process started.
Concerning identity: we should leave this to the "rules group" because it is a technical aspect: there are lots of methods for KYC out there and probably very soon we'll have some not being based on official identity documents - combine any of these with your account-name and you're registered.