Since most of the custom fields for pages are inheriting from the user's custom fields, you can modify the custom field theme file for the user fields.

For instance, if you are trying to add contents on the theme file for textbox field on a page, you could copy the file from /media/com_easysocial/apps/fields/user/textbox/themes/default/display_content.php into /media/com_easysocial/apps/fields/page/textbox/themes/default/ and make your changes accordingly.

It is currently not possible to have links on the custom fields from pages as the search area doesn't support that now.