Regarding the blocking of access, since everything runs on the Steem blockchain, as long as you can access the blockchain somehow - you should be able to access your account and funds. For example you could use @jesta’s vessel desktop wallet and just point to any one of the public RPC nodes.

The one account one vote idea is related to SMT oracles. It would actually benefit smaller stakeholders the most since everyone’s votes would be equal. The oracle SMT implementation assumes there are “oracles” that will be verifying the uniqueness of individuals, so people cannot signup for multiple accounts.

Not sure where you are going with the central authority idea. I don’t know under what scenario that would ever happen with Steem.