Thanks for the advice.
It's good advice.
For the benefit of future non-tech readers, I guess I'll add a few more comments.
If you make an effort to clean up CSS, your first step should be to backup and archive the full rule set. You may need it if the cleanup breaks your site, and you may need it for future site mods. It's not difficult to revert back to the full rule set. Just delete the cleaned set, upload the full set, and edit head.tpl as needed.
Not to be argumentative, but a cdn is a geographically dispersed set of servers that attempts to load content to users faster by choosing servers closer to the user's location from which send all or parts of your content. At nearly lightspeed, chopping 3000 miles off the content's journey will save less time than significantly reducing the filesize of the content. I think cdn's must be a great idea for huge sites, but i see little potential benefit for small sites.
If you're on a fast server already, this part of the job is already done.
Optimize thumbs is a good idea.
Writing good content is essential.
I worked hard to write good content, so i hope Basara's suggestion is more a general one, and not specifically directed at my site. :-)
If you choose a fast host, write good content, and optimize all images, and if everything else is running properly, your site will load fast.
Mine does. It's really pretty fast.
But if you want, you can also cut your css file load in half, combine and minify, and you will be even faster. Does it matter? Some say yes, some say no. If you hack the css up, you risk losing responsive features or breaking your site. That is why my original suggestion was to take a conservative approach.
The uncss grunt was written by a google executive. It has selectable levels and filters. It is widely used. You can apply ignore blocks to all @media rules, etc, etc. So if you spend just a little time during setup, it is quite possible to clean css without breaking AC, and it is always possible to revert.
Closing comment: Basara gave good advice.