If you want members to be able to login and be able to add and edit their own entry in the directory
Ok. How can I be sure that they modify only THEIR entry?
The WP User at a Subscriber role does not have much more privileges that a not logged in user. They can maintain the email and password and that is about it. You would configure Link but not enable the “Submit Entry” link
How can I allow them to modify all the fields?
Thank you!