I created a user who can add members.
Is it possible to hide the field 'Admin field', 'Images' and 'Biography' on a profile page in the admin?
Just turn on "Show system templates" in the template list.
Edit the template level field settings as usual:
If you have the great Custom Inputfield Dependencies module by @Robin S installed, you can easily implement any sort of custom visibility (even by using PHP and the PW API).