Example gratuitous complications: I don't want my address updated if my neighbour shares my address and he moves; if my partner breaks up with me on really bad

Example gratuitous complications: I don't want my address updated if my neighbour shares my address and he moves; if my partner breaks up with me on really bad terms and I move I don't want to share my new address. Probably, what's wrong is the concept of people having a relation with addresses while the actual relation is between a shipping and its target address. An example of doing it right: Backerkit (a site for crowdfunding-related surveys and orders) asks for an address every time there's something to send, and only later suggests using a similar previously entered address instead. No "updating", only separate transactions with their respective shipping addresses, all explicitly decided by the customer with some assistance in data entry.