There is a very important support article out there, about what you can do if your SharePoint is sometimes very slow.
E.g.: on the first start of a Site
Sometimes during the day a search query will take about a minute until you get results.....
Just look on that article: http://support.microsoft.com/kb/2625048
it will improve your "feeled" performance (site response times) massive, if you're going to implement both solutions.
Disabling CRL Check is just neccassary if the SP Server does not have internet connectivity! -> that means proxy settings must be configured for the server itself
http://technet.microsoft.com/de-de/library/bb430772(v=exchg.141).aspx, and your proxy must allow traffic from the server of course.
It is NOT enough that you're able to browse through the Internet on your SP Server!!!