Wp-adminフォルダの名前を変更できますか？

.htaccess

function my_custom_admin_url($path) { 
    return str_replace('wp-admin', 'dashboard', $path); 
}
add_filter('admin_url', 'my_custom_admin_url');

function whats_my_admin_url() {
    $url = admin_url();
    echo '<pre><code>'; print_r( $url ); echo '</code></pre>';
    }
add_action( 'admin_notices', 'whats_my_admin_url' );

#CUSTOM ADMIN URL REWRITE
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^dashboard[^/]*$ dashboard/ [R=301,L]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^dashboard(.*)$ wp-admin$1? [QSA,L,NE]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^wp-admin/?$ / [NE,R=404,L]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^wp-admin/(.*)$ dashboard/$1 [QSA,R=301,L,NE]
</IfModule>
#CUSTOM ADMIN URL REWRITE

<?php
/**
 * Plugin Name: Change My Admin URL
 * Plugin URI: http://wordpress.stackexchange.com/questions/106/can-i-rename-the-wp-admin-folder
 * Description: Changes the admin url where wp-admin becomes dashboard (or whatever you change it to)
 * Version: 1.0
 * Author: Bryan Willis
 * Author URI: http://profiles.wordpress.org/codecandid
 * License: GPL2
 */

/* 

#CUSTOM ADMIN URL REWRITE FOR HTACCESS
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^dashboard[^/]*$ dashboard/ [R=301,L]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^dashboard(.*)$ wp-admin$1? [QSA,L,NE]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^wp-admin/?$ / [NE,R=404,L]
RewriteCond %{QUERY_STRING} (.*)$
RewriteRule ^wp-admin/(.*)$ dashboard/$1 [QSA,R=301,L,NE]
</IfModule>
#CUSTOM ADMIN URL REWRITE

*/

function my_custom_admin_url($path) { 
    return str_replace('wp-admin', 'dashboard', $path); 
}
add_filter('admin_url', 'my_custom_admin_url');

<?php
define('WP_ADMIN_DIR', 'admin');
defined('SITECOOKIEPATH') || define('SITECOOKIEPATH', preg_replace('|https?://[^/]+|i', '', get_option('siteurl') . '/' ) );
define( 'ADMIN_COOKIE_PATH', SITECOOKIEPATH . WP_ADMIN_DIR);

add_filter('site_url',  'wpadmin_filter', 10, 3);
 function wpadmin_filter( $url, $path, $orig_scheme ) {
  $old  = array( "/(wp-admin)/");
  $admin_dir = WP_ADMIN_DIR;
  $new  = array($admin_dir);
  return preg_replace( $old, $new, $url, 1);
}

add_action('init', 'redirect_wp_admin_url_to_404');
function redirect_wp_admin_url_to_404(){
  $redirect_to = $_SERVER['REQUEST_URI'];
  if(count($_REQUEST)> 0 && array_key_exists('redirect_to', $_REQUEST)){
    $redirect_to = $_REQUEST['redirect_to'];
    $check_wp_admin = stristr($redirect_to, 'wp-admin');
    if($check_wp_admin){
      wp_safe_redirect( '404.php' );
    }
  }
}

AuthUserFile /dev/null
AuthGroupFile /dev/null
AuthName "WordPress Admin Access Control"
AuthType Basic
<LIMIT GET>
order deny,allow
deny from all
whitelist address
allow from <IP ADDRESS HERE>
</LIMIT>

<?php
if(!is_page('admin')): //if not the admin page.

//wrap code not needed or wanted.

else: ?>

<style type="text/css">
    .responsive-iframe {
    position: relative;
    padding-bottom: 56.25%; /*16:9*/
    height: 0;
    overflow: hidden;

    iframe {
        position: absolute;
        top:0;
        left: 0;
        width: 100%; //or 100vw
        height: 100%; //or 100vh
    }
}   
</style>

<div class="responsive-iframe">
<iframe seamless="seamless" scrolling="yes" src="http://yourdomain/wp-admin/" frameborder="0" allowfullscreen></iframe>
</div>

<?php 
endif;

Wp-adminフォルダの名前を変更できますか？

更新：代替アプローチ