Share password protected posts via secret URLs

Make the WordPress post state text (draft, pending, sticky, etc) stand out.

Use WP Customize to modify elements of password protected and private posts and pages.

Reset post or page password automatically after X days.

The Whitelist plugin enables you to open your website to a set of users and blocks everyone else. You can enter users by their email address into the Whitelist tab of the plugin. Once done, only users on the list would be able to visit your site.