Apache mod_rewrite query string before page and remove extention - apache

Question

I've scavenged the web for answers to my mod_rewrite woes and I feel I'm at the end of my wits. I will have a URL like such: http://www.website.com/dashboard.php?username=stackoverflow. This url isn't the prettiest of such. So my goal is to do a few things here...
Eliminate the extension of the php file (I've been able to do this so far with the code I'll show below, but I don't know that it will stay according to the other things I need to do)
Eliminate the "www" prefix
Move the username query string (only if it's "username", I don't want to match "id" or such) directly after ".com/"
Move the php filename (without the extension) after query string.
The final URL should look like such: http://website.com/stackoverflow/dashboard or perhaps http://website.com/stackoverflow/profile.
The code I have right now which eliminates the file extension is such:
Options +FollowSymLinks
RewriteEngine On
RewriteBase /
# remove .php ONLY if requested directly
RewriteCond %{THE_REQUEST} (\.php\sHTTP/1)
RewriteRule ^(.+)\.php$ /$1 [R=301,L,QSA]
# remove trailing slash ONLY if it is not an existing folder
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ /$1 [L,R=301]
# rewrite to FILENAME.php if such file does exist and is not a folder
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*)$ /$1.php [L,QSA]
Sadly this only fixes one of my issues and after looking at it, I'm getting the feeling there would be a better way to do this...

Answer 1

(1, 3, 4) As I understand you want to use pretty URLs, but backed by PHP pages. So it should be like this:
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(\w+)/profile$ /dashboard.php?username=$1 [L]
It will make http://website.com/stackoverflow/profile working as http://www.website.com/dashboard.php?username=stackoverflow
(2)
# Redirect www.site.com to site.com with 301
RewriteCond %{HTTP_HOST} ^www\.(.+)$ [NC]
RewriteRule ^(.*)$ http://%1/$1 [R=301,L]