Редирект 301+Robots.txt - правильно иди нет ?

User-agent: * 
Disallow: /admin/
Disallow: /core/
Disallow: /languages/
Disallow: /users/
Disallow: /core/
Disallow: /board/
Disallow: /books/
Disallow: /rss/
 
User-agent: Yandex
Disallow: /
 
Host: navigator-bg.ru

Options +FollowSymLinks
RewriteEngine On
RewriteCond %{HTTP_HOST} ^navigator-bg\.ru$ [NC]
RewriteRule ^(.*)$ http://www.navigator-bg.ru/$1 [R=301,L]

AddDefaultCharset windows-1251
RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.navigator-bg\.ru(.+)$ [NC]
RewriteRule ^(.*) http://navigator-bg.ru%1/$1 [L,R=301]
 
RewriteBase /
RewriteRule ^.htaccess$ - [F]
 
RewriteCond %{REQUEST_URI} !\.(jpg|jpeg|ico|gif|png|css|xml|js|pl|txt)$ [NC]
RewriteCond %{REQUEST_FILENAME} !^/admin
RewriteCond %{REQUEST_FILENAME} !^/migrate
RewriteCond %{REQUEST_FILENAME} !^/install
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
 
RewriteRule ^(.*)$ /index.php [L]

RewriteCond %{HTTP_HOST} ^www.navigator-bg\.ru(.+)$ [NC]
RewriteRule ^(.*) http://navigator-bg.ru%1/$1 [L,R=301]

RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
RewriteRule ^(.*) http://%1/$1 [L,R=301]