Redirect state after user registers without confirmation email

How about overriding the effects of all hook_form_alter() invocations by declaring a #after_build callback?

e.g. in mymodule_hook_form_alter()

$form['#after_build'][] = 'mymodule_user_register_after_build';

then

/**
 * Callback function using after_build on user_registration form.
 */
function mymodule_user_register_after_build($form, &$form_state) {

  // Add callback to enforce redirection.
  $form['#submit'][] = 'mymodule_user_register_submit';

  return $form;
}

/**
 * Callback function for registration form submit.
 */
function mymodule_user_register_submit($form, &$form_state) {
  $form_state['redirect'] = 'mypath1/mypath2';
}

As long as no other modules have #after_build callbacks, you should be able to add your own submit function after whatever the other modules (including email_registration) have put in $form['#submit']. If your function sets $form_state['redirect'] and gets to be the last piece of code to do so, your personal redirect will be the one that is used.

I am trying to integrate FBConnect, email_registration and Content Profile with my own custom login/registration requirements, so this is a hot topic for me, but I can see that if contributed modules use this approach to override other contributed modules it becomes something of an arms race as to who gets last go at the $form variable!

I commented out #125 and #124 (registration confirmation message). I use rules to direct new users to a special page and this was preventing that from happening.

An admin option would be nice or perhaps just removing all together, unless I am missing something.

It looks like this was added in #648450: No e-mail verification required autologin.

You can override this behavior as described in #1 or by setting a $_REQUEST['destination'] - see http://drupal.stackexchange.com/questions/5440/form-redirect-not-working... for more details on the latter idea.