The postal address issue seems pretty intractable, to me. A PO Box would provide another layer of indirection, but is also a subpoena (or less in many countries) away from revealing my identity. . .
This came up in a recent discussion I was involved in. By the end of the discussion, we decided that for the right price (or the right persuasion technique) you might be able to convince a complete stranger to acquire a P.O. Box and turn the key over to you. Then, in case of the small chance that authorities might stake out the box and wait for you to collect the contents, you might be able to convince (pay) a new stranger to run in, collect the contents, and bring them out to you while you wait at a safe distance where you can keep an eye on the exit.