As to why stress the CPU for faster access, Ifigure I'm paying my host for the CPU so that my visiters can get the best experiance. Of course in a random stroke of irony I have had to change hosts, I'm now hosting on Merlins Camalot, and can't use some of these tricks. :) His hosting is in all other ways wonderfull though, and the servers are so fast it doesn't matter much.

As for the CSS optimizer messing up your code, that should not be possible. My guess is that you have an error in your CSS. Did you use the w3c validator first?