If you click on the FS2004 Add-on Manager it says check for up-dates with Zurich, can I use that instead of downloading the latest version.
That option has never been used and, in fact, it has been removed from the latest Addon Manager, because it's not really possible for a module and a scenery to update itself when FS is running.
I also have different Cloud 9 airports like LA and Amsterdam, will these be affected, which new Add-on Manager I need.
As long as you have the latest version available from Cloud9, you shouldn't be concerned at all, it's all backward compatible, and we are keeping track of all updates (easy for us, since we did all Cloud9 sceneries...). If you have an older version of a scenery, you'll get a warning, that would be solved by simply updating the affected scenery.
Have the CD 4 to start the Flight Simulator and have a normal computer, 1024 Mb Ram, Video Nvidia 128 mb. etc, so I do not need the 2 GB. patch.
As I've said in other thread, there's no reason to be concerned of the 2GB patch. The installer will detect which FS9.EXE you have, and will install the correct version automatically. This has been fixed some hours after the initial release of the installer, so the people that had problems, were only those that downloaded the installer in the first hours.