Add new line in phone/email fields?

Those are simple text inputs, which are sanitized before saving to the database, and also properly escaped before display on the public side, as per proper security procedure to prevent exploits of your site.

What you are asking for is a feature request, and is not a support issue, as those would need to be changed to text areas, with different checks to sanitize and escape while still allowing some html tags (such as line breaks). That falls under the feature request category.

However, you can use the Custom Fields extension, right now, to easily add a second phone number field to your directory:

https://stephensherrardplugins.com/plugins/pta-member-directory-custom-fields/