Hi Judi,
All the programs you stated above do different purposes. Norton I do not beleive can get rid of spyware issues, that is what the adaware and spybot are used for. Norton is more along the lines of System Mechanic, both are good programs. But as you said Norton does require some more juice in the machine to work better.
If you are looking for a replacement anti-virus software, you can try a number of them in our download section. Myself I still prefer Norton, as it is easy to use and offers great protection. Everyone will have their own chocies on Anti-virus software, but for my clients I recommand using Norton Anti-Virus.
As for duplicates, usually it is ok to get rid of them, but it's best to make sure that you know what the files are. I beleive you just did a system restore on your computer from the past threads, so I'm not really sure that you would have many duplicate files.
