But if Google decides to nuke me from orbit, and my domain is registered there, the nuke can cross between my domain and my Google account.

Well, yeah, that's digital monopolies for you. I guess one can always create a dedicated google account to register each site with

It doesn't work, there was a Google employee here mentioning they assign a degree of separation to each account, any accounts that are deemed "close", are included when the ban hammer falls.

Google ties your accounts together on the backend though if they realise they're related, so this isn't as easy as it sounds.