That is why that kind of installation (dumping the archive in the docroot of a shared hoster) is NOT the recommended way to install
*pgsql is only needed if you plan to use PostgreSQL, that’s why it is only yellow (warning) and not red (error).
Same is true for ldap, not needed if you store accounts in the database.
tidy is a different story, it is needed to clean up office documents created by merge-print. But to get a PHP extension you need to talk to your hoster or consult with his documentation.