Having run RAID quite a bit myself one must remember having all your drives in one box is always an invitation for trouble since hardware failures on a higher order will likely hit all the drives.
If you want to do online backup get DSL instead of cable internet for the faster upload bandwidth.
Get a backup service with versioning. That way if you or a virus delete something it just doesn't sync the deletion to your backup.
I personally use JungleDisk which uses Amazon S3 storage. You can set the versioning controls and you only pay for the storage/bandwidth you use. My bill averages about $2/mo for several gigs.
Yes I heard it has gotten better over years but I still see computer after computer crippled by their bloated software. It wouldn't surprise me if it was a rootkit of some sort which was used in older versions of Systemworks.
I got rid of Norton after I saw such a huge hit I was taking on startup time and hard drive access time. If you check comparatives on anti-virus products you'll find many offer the same or better protection without the performance hit.
Personally I have been very happy with Nod32 by ESET. Its startup is slower on my personal vs. work machine and I had to have it exclude some areas for false positives but overall it has been very efficient.
May Euell Gibbons eat your only copy of the manual!