Anonymous user can't view CiviCRM user dashboard in WordPress
So, to close the loop on this, the answer is this:


inside WP, but outside CiviCRM, the checksum and cid need to be identified on the GET string as cs and id respectively
inside CiviCRM, the checksum stands alone (no separate variable, though it seems to work as cs too) and the client id must be cid as id is used for other purposes in CiviCRM.


I discovered no way to cleanly pass these values through a page. I used a PHP insertion plugin to Wordpress to extract the values from the $_GET global array and pass them back into the page.

Thanks to Demerit in helping me figure this out.