htaccess - optimal settings and best practices.

currently my htaccess file looks like this

# Comment the following line (add '#' at the beginning)
# to disable mod_rewrite functions.
# Please note: you still need to disable the hack in
# the vBSEO control panel to stop url rewrites.
RewriteEngine On

# Some servers require the Rewritebase directive to be
# enabled (remove '#' at the beginning to activate)
# Please note: when enabled, you must include the path
# to your root vB folder (i.e. RewriteBase /forums/)
#RewriteBase /

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

RewriteRule ^((urllist|sitemap_).*\.(xml|txt)(\.gz)?)$ vbseo_sitemap/vbseo_getsitemap.php?sitemap=$1 [L]

RewriteCond %{REQUEST_URI} !(admincp/|modcp/|cron|vbseo_sitemap)
RewriteRule ^((archive/)?(.*\.php(/.*)?))$ vbseo.php [L,QSA]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !/(admincp|modcp|clientscript|cpstyles|images)/
RewriteRule ^(.+)$ vbseo.php [L,QSA]

Should I be enabling gzip, exprires headers and other tricks to speed up the site?

Im on apache using php version 5.2.17

any tips?

Server and caching optimizations are beyond the realm of our support.

It's better to enable gzip