Is it possible to switch from a private filesystem to a public one in Drupal. If so how would you do this?
/admin/settings/file-system says Changing the download method will modify all download paths and may cause unexpected problems on an existing site..
I believe the private file method generates a link that runs the user through the access control to ensure they have the right to download a file. The part about links changing may allude to file links inside the content, or may also pertain to file paths in the database. If you have the files folder outside of the root, setting to public will definitely break links on the site.