Update? I don’t think so, as the driver in the repo isn’t usually up to date.
If you want/need to install/reinstall the latest ATI driver you can follow this method and use this script: Upgrading ATI driver with atiupgrade . There are other methods which work as well.
If you don’t have the latest ATI card and don’t need the latest driver, installing from the repo should be fine.
Oh, ok. I would assume it does. … but don’t know 100%, as I don’t have that Xorg version. You could make sure that the following files - belonging to the fglrx package - don’t get overwritten: *