how do i show/hide category icons when viewing recent searches or favorites lists?

Yes.  From the main screen, select Options (Right Soft Key) and then Preferences.  Select General.  Use the up and down Rocker Key to select Show Recent/Favorite Icons.  Press Set (Left Soft Key) so that the box next to the option is checked to show the icons or unchecked to hide them.  Press OK to save the setting.