On my site I've removed all of the CSS files which came with the template (e.g. body.css, template.css, thirdparty.css, etc), and have made Joomla retrieve CSS from one new CSS file "website.css". The website.css contains some portions of the standard CSS files from the template in it - does this mean I need to include the standard RT css copyright information at the top of my new CSS?
i moved everything into a single file in order to keep it all in one place and speed up load times.
not as far as I know but if the intention was to reduce css from causing multiple http requests then rokbooster (for Joomla 2.5 sites) would do a much better job of doing this. RokGzipper (for Joomla 1.5 sites)
There are several css files that are browser specific and combining them manually can create some major issues from browser to browser.