forward links should be inserted only if type == 'node' or type=='comment'

Fixed in HEAD and 5.x. Thanks.

The way this is implemented, the forward link/form is on by default. I think that it is generally better practice to have to turn it on per content type rather than off. This is a one digit fix, line 637 in HEAD:

  if ('node_type_form' == $form_id) {
    $form['workflow']['forward_display'] = array(
      '#type' => 'checkbox',
      '#title' => t('Show forwarding link/form'),
      '#return_value' => 1,
      '#default_value' => variable_get('forward_display_'. $form['#node_type']->type, '0'),
      '#description' => t('Displays the form/link to allow visitors to forward the page to a friend. Further configuration is available on the !settings.', array('!settings' => l(t('settings page'), 'admin/settings/forward' ))),
    );
  }

I just changed

      '#default_value' => variable_get('forward_display_'. $form['#node_type']->type, '1'),

to

      '#default_value' => variable_get('forward_display_'. $form['#node_type']->type, '0'),

Thanks for your work on this!

I'd prefer not to change this since every site I've used it on prefers to have it on for most if not all content types. It's configurable as is, and I prefer to leave it with the default that is least likely to need to be changed by the widest number of users.

FWIW, I'm planning on looking in to adding the list of content types to the forward settings page so it can be changed there, too. That'd save someone like you a lot of clicks. ;-)