Ctrl+F1 through Ctrl+F4 are not hard coded, you can change them in the Keyboard Shortcut settings in KDE 4's System Settings.
Menu -> Settings -> System Settings
You can also set up your "switch to next desktop" shortcut as well in here.
Ctrl+F1 through Ctrl+F4 are not hard coded, you can change them in the Keyboard Shortcut settings in KDE 4's System Settings.
Menu -> Settings -> System Settings
You can also set up your "switch to next desktop" shortcut as well in here.