Speed up website done correctly - performance

Question

I want to speed up my website. I was wondering I've done it correctly syntax wise.
<IfModule mod_expires.c>
Header unset Pragma
FileETag None
Header unset ETag
ExpiresActive On
ExpiresDefault "access plus 1 year"
##### DYNAMIC PAGES
<FilesMatch "\\.(ast|php)$">
ExpiresDefault A7200
Header set Cache-Control "public, max-age=3600, must-revalidate"
</FilesMatch>
##### STATIC FILES
<FilesMatch "(?i)^.*\.(ico|png|gif|jpg)$">
Header unset Last-Modified
Header set Expires "Fri, 21 Dec 2012 00:00:00 GMT"
Header set Cache-Control "public, no-transform"
</FilesMatch>
<FilesMatch "\\.(css|js|xml)$">
Header set Cache-Control "public, max-age=604800, must-revalidate"
</FilesMatch>
</IfModule>

Answer 1

Do not cache asp or php or any dynamic page! This will cause unpredictable result.
Here's an example, say you have a page called catalog.php that renders the product catalog with uptodate price and stock availability. Since you have set it to cache the result on browser for an hour, it will show stale data on browser for an hour!
Dynamic pages should never be cached wholesale like this. You need to put individual caching logic on pages based on how fresh the data should be returned from the page.
For static pages though you can do such wholesale expiration. However, be careful that if you set css and js files to expire after one year, a user who visits your site today will not fetch latest js and css from webserver for many days or months. If you make changes to the scripts or style, they will not see the changes unless you use some unique querystring to change the url of the files manually.
I have discussed an approach here that works for ASP.NET only. But it tells you about the dos and don'ts.
http://omaralzabir.com/automatic-javascript-css-versioning-to-refresh-browser-cache/
You can also read my 7 tips for making best use of caching that explains all such approaches and pros and cons of each:
http://omaralzabir.com/making_best_use_of_cache_for_high_performance_website/
Let me know if this helps.

Answer 2

I am aware the question is from 2011 but even then, Pragma was old. I think it is safe to stop using it.
We rarely need to set 'public' or must-revalidate unless your trying to support really old browsers and proxies like pre IEv4 and stuff.
If your going to cache your php you still need to do some work in your php code too.
Unsetting your Last-Modified for images and stuff is essentially causing a 'never cache' situation for those files until the predetermined date of the static (at the time) future date. I would think you want to cache static files X days in future always and not unset last modified.
Your htaccess file can be made to be much simpler. Borrowing some snippets from H5BP we can modernize it a bit to become:
## set some mime types to their proper types
AddType application/javascript js jsonp
AddType application/json json
AddType application/xml rss atom xml rdf
AddType image/x-icon ico
<IfModule mod_deflate.c>
# Force deflate for mangled headers developer.yahoo.com/blogs/ydn/posts/2010/12/pushing-beyond-gzipping/
<IfModule mod_setenvif.c>
<IfModule mod_headers.c>
SetEnvIfNoCase ^(Accept-EncodXng|X-cept-Encoding|X{15}|~{15}|-{15})$ ^((gzip|deflate)\s*,?\s*)+|[X~-]{4,13}$ HAVE_Accept-Encoding
RequestHeader append Accept-Encoding "gzip,deflate" env=HAVE_Accept-Encoding
</IfModule>
</IfModule>
# Compress all output labeled with one of the following MIME-types
# (for Apache versions below 2.3.7, you don't need to enable `mod_filter`
# and can remove the `<IfModule mod_filter.c>` and `</IfModule>` lines as
# `AddOutputFilterByType` is still in the core directives)
<IfModule mod_filter.c>
AddOutputFilterByType DEFLATE application/atom+xml \
application/javascript \
application/json \
application/rss+xml \
application/vnd.ms-fontobject \
application/x-font-ttf \
application/xhtml+xml \
application/xml \
font/opentype \
image/svg+xml \
image/x-icon \
text/css \
text/html \
text/plain \
text/x-component \
text/xml
</IfModule>
</IfModule>
<IfModule mod_expires.c>
ExpiresActive on
ExpiresDefault "access plus 1 month"
# Your document html
ExpiresByType text/html "access plus 0 seconds"
# Data
ExpiresByType application/json "access plus 0 seconds"
ExpiresByType application/xml "access plus 0 seconds"
ExpiresByType text/xml "access plus 0 seconds"
# Feed
ExpiresByType application/atom+xml "access plus 1 hour"
ExpiresByType application/rss+xml "access plus 1 hour"
# Favicon (cannot be renamed)
ExpiresByType image/x-icon "access plus 1 week"
# images
ExpiresByType image/gif "access plus 1 month"
ExpiresByType image/jpeg "access plus 1 month"
ExpiresByType image/png "access plus 1 month"
# CSS and JavaScript
ExpiresByType application/javascript "access plus 1 year"
ExpiresByType text/css "access plus 1 year"
</IfModule>
# ----------------------------------------------------------------------
# Prevent mobile network providers from modifying your site
# ----------------------------------------------------------------------
# The following header prevents modification of your code over 3G on some
# European providers.
# This is the official 'bypass' suggested by O2 in the UK.
<IfModule mod_headers.c>
Header set Cache-Control "no-transform"
</IfModule>
# ----------------------------------------------------------------------
# ETag removal
# ----------------------------------------------------------------------
# FileETag None is not enough for every server.
<IfModule mod_headers.c>
Header unset ETag
</IfModule>
# Since we're sending far-future expires, we don't need ETags for
# static content.
# developer.yahoo.com/performance/rules.html#etags
FileETag None

Answer 3

Google has a website that will help you analyze your site. There are a number of tools and helpful analysis available with this tool.
https://developers.google.com/speed/