Screensaver is located in the registry at
HKCU\Control Panel\Desktop

There you can see all the settings, you need as far as the screensaver goes, I would use VB for this project, there are a number of activex controlls that handle registry edits/queries and most of them are free.

Live update information for norton can be found at
HKLM\software\symatec\shareddefs\microdefs

There you can get the date of the last definitions update, not sure how to tell if it has been ran, I will try and figure it out and get back to you.