OK, since this thread was hijacked, i guess it is pretty worthless now, the intent was to get some responses which pretty much all add up to one thing.
If you have an account that can only write to the files you REALLY need to write too, then a virus (or any malicious code for that matter) that is run while you are logged in can only affect those files.
That is, your system, except for your own home folder, is safe even if your AV fails to catch the virus or whatever malicious code that is being executed.
That was my point, but since all of you already know everything, i assume it is lost on you.