Für Codes bitte immer das "Code"-Fenster benutzen. Das erhöht die Lesbarkeit um ein Vielfaches!

Wenn dein Shop in einem Unterverzeichnis liegt, dann musst du es mit angeben: http://www.domain.de/shop/

So sollte es dann bei dir aussehen:
Code:
RewriteEngine on

RewriteCond %{REQUEST_URI} ^/$ [OR]
RewriteCond %{REQUEST_URI} ^/index\.html$
RewriteRule ^.*$ http://www.domain.de/shop/ [R=301,L]

RewriteCond %{REQUEST_FILENAME} ^(.*)\.(php|css|js|gif|jpg|jpeg|png)$ [NC]
RewriteRule ^(.+) - [L]

RewriteCond %{REQUEST_URI} (.*)?/admin/(.*)
RewriteRule ^(.+) - [L]

RewriteCond %{REQUEST_URI} (.*)?/images/(.*)
RewriteRule ^(.+) - [L]

RewriteCond %{REQUEST_URI} (.*)?/templates/(.*)
RewriteRule ^(.+) - [L]


RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^(.+) - [L]

RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^(.+) - [L]

RewriteCond %{REQUEST_FILENAME} -l
RewriteRule ^(.+) - [L]


##boosted BLOG-ITEMS
RewriteRule (.*/)?Blog/([A-Za-z0-9_-]+)/([A-Za-z0-9_-]+)\.html.* blog.php?blog_cat=$2&blog_item=$3 [PT,L]

##boosted BLOG-CAT
RewriteRule (.*/)?Blog/([A-Za-z0-9_-]+)/?.* blog.php?blog_cat=$2 [L]

##boosted BLOG-START
RewriteRule (.*/)?Blog/ blog.php [L]

##boosted CONTENT
RewriteRule (.*/)?info/([A-Za-z0-9_-]+)\.html.* shop_content.php?gm_boosted_content=$2&%{QUERY_STR ING} [PT,L]

##boosted PRODUCTS
RewriteRule (.*/)?([A-Za-z0-9_-]+)\.html product_info.php?gm_boosted_product=$2&%{QUERY_STR ING} [PT,L]

##boosted CATEGORIES
RewriteRule (.*/)?([A-Za-z0-9_-]+)/?.* index.php?gm_boosted_category=$2&%{QUERY_STRING} [L]