Copy data of Email in registration to the username not showing in the registration page
The Email Registration module will allow for using the email address as the username.

The LoginToboggan module will allow the user to create a username, and allow them to login with either the username OR email address.

Email Registration also provides a hook which will allow a custom module to set the account name to whatever you want it to be.  That does require writing a module, however, it doesn't have to be very complicated.

The only thing you would need to include in your module file is the hook.
Example adapted from http://www.grasmash.com/article/using-your-email-address-your-drupal-username#sthash.uZkOo6j6.dpuf

&lt;?php
/* 
* Implements hook_email_registration_name().
*/
function grasmash_email_registration_name($edit, $account) {
  return $account-&gt;mail;
}