Opencart remove redirect 302 to index?route=common/home .htaccess

Question

I have this opencart website, where I want to do 2 things with the .htaccess file.

First: Always put www before the domain, unless it is a subdomain. Second: Take out the index?route=common/home from the index page and keep it with the / only

I am able to all that, but I think the redirects are making my website slower to load, maybe because of some redirect loop, but I can't identify the problem.

My .htaccess is this one:

# Prevent Directoy listing
Options -Indexes

# Prevent Direct Access to files
<FilesMatch "\.(tpl|ini|log)">
 Order deny,allow
 Deny from all
</FilesMatch>

# SEO URL Settings
RewriteEngine On
# If your opencart installation does not run on the main web folder make sure you folder it does run in ie. / becomes /shop/

#BASE
RewriteBase /

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

#o index ser / e não index?route=common/home
RewriteCond %{THE_REQUEST} ^[A-Z]{3,}\s/+index\.php\?route=common/home[?\s] [NC]
RewriteRule ^ /? [R=301,L]

#seo friendly
RewriteRule ^sitemap.xml$ index.php?route=feed/google_sitemap [L]
RewriteRule ^googlebase.xml$ index.php?route=feed/google_base [L]
RewriteRule ^download/(.*) /index.php?route=error/not_found [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_URI} !^/$
RewriteCond %{REQUEST_URI} !.*\.(ico|gif|jpg|jpeg|png|js|css)
RewriteRule ^([^?]*) index.php?_route_=$1 [L,QSA]

## EXPIRES CACHING ##
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access plus 1 week"
ExpiresByType image/jpeg "access plus 1 week"
ExpiresByType image/gif "access plus 1 week"
ExpiresByType image/png "access plus 1 week"
ExpiresByType text/css "access plus 1 week"
ExpiresByType application/pdf "access plus 1 week"
ExpiresByType text/x-javascript "access plus 1 week"
ExpiresByType application/x-shockwave-flash "access plus 1 week"
ExpiresByType image/x-icon "access plus 1 week"
ExpiresDefault "access plus 1 week"
</IfModule>
## EXPIRES CACHING ##

### Additional Settings that may need to be enabled for some servers
### Uncomment the commands by removing the # sign in front of it.
### If you get an "Internal Server Error 500" after enabling any of the following settings, restore the # as this means your host doesn't allow that.

# 1. If your cart only allows you to add one item at a time, it is possible register_globals is on. This may work to disable it:
# php_flag register_globals off

# 2. If your cart has magic quotes enabled, This may work to disable it:
# php_flag magic_quotes_gpc Off

# 3. Set max upload file size. Most hosts will limit this and not allow it to be overridden but you can try
# php_value upload_max_filesize 999M

# 4. set max post size. uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
# php_value post_max_size 999M

# 5. set max time script can take. uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
# php_value max_execution_time 200

# 6. set max time for input to be recieved. Uncomment this line if you have a lot of product options or are getting errors where forms are not saving all fields
# php_value max_input_time 200

# 7. disable open_basedir limitations
# php_admin_value open_basedir none




# GZIP -> MAKE WEBSITE LOADING FASTER 18-may-06 nh_design
# compress text, html, javascript, css, xml:
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/xml
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/x-javascript

# Or, compress certain file types by extension:
<files *.php>
SetOutputFilter DEFLATE
</files>

And I checked the redirects through this website http://redirectdetective.com/ with this result:

Between that 302 to put the index?route=common/home and the 301 to only put the www before the domain, I think it's where the redirect loop is.

I would really appreciate some help, and if any more info is needed, I'll be glad to add.

Thank you!