How create a multisite setup with “phantom” accounts and passwords?

  1. Your (super) admins will still be able to edit users’ details — it’ll just be a two-step process. First they’ll create the user; then, they’ll go to the new user’s details page (eg, example.com/wp-admin/network/user-edit.php?user_id=[xxx]) to edit the user’s details.

  2. I’m not sure I comprehend the second question. Do you require that readers of your online newspaper log in to WordPress before they can read the paper? If so, they should be set up as Subscribers — see the Codex docs on Roles and Capabilities for a primer on WordPress’s built-in roles and those roles’ respective capabilities.