How can I hide the username on a custom user-profile.tpl.php page?
You can do it by disable field display property using form_alter

function mymodule_form_alter(&amp;$form, &amp;$form_state, $form_id) {
  if ($form_id == 'FORM_ID') {
  $form['account']['your_field_name']['#access'] = FALSE;
    }
  }