Rik, thank you so much for these detailed analysis i'll definitely going to modify the changes you have pointed out.
But you know i was more concerned about same website on dedicated server (http://www.essaysbundle.com) which is taking so long to open a single page.
After 3 weeks of effort and discussion with users like you i have found the problem but still looking for good solution.
After migration from shared to dedicated server the main problem was the speed that i used to get more than 30 seconds to open one page on dedicated server but today i have reached to the exact problem.
THe problem is SEO Ceon URI Mapping if i disable it then i'm getting this time on my dedicated server
Parse Time: 0.297 - Number of Queries: 219 - Query Time: 0.07835233895874
Which i think is much better.
Now the server goes down as soon as i turn on SEO Ceon URI mapping.
I can't turn it off because all my webpages are indexed with this Ceon URI mapping with Google.
Please suggest me the solution
Here is the .htaccess file used at shared hosting but when it is used on dedicated it gives low performance:
RewriteEngine On
Don't rewrite any URIs ending with a file extension (ending with .[xxxx])
RewriteCond %{REQUEST_URI} !.[a-zA-Z]{2,4}$
Don't rewrite admin directory
RewriteCond %{REQUEST_URI} !^/admin.* [NC]
Don't rewrite editors directory
RewriteCond %{REQUEST_URI} !^/editors.* [NC]
Don't rewrite cPanel directories
RewriteCond %{REQUEST_URI} !/cpanel.* [NC]
RewriteCond %{REQUEST_URI} !/frontend.* [NC]
Handle all other URIs using Zen Cart (index.php)
RewriteRule (.*) index.php?%{QUERY_STRING} [L]
#RewriteCond %{HTTP_HOST} ^essaysbundle.com$ [NC]
#RewriteRule ^(.*)$ http://www.essaysbundle.com/$1 [R=301,L]