Thank you: "iisforiphone", "simsaladimbamba" and "theSeb" for your responses.
I will definitely start CCC as a secondary backup (in addition to TM).
Last question . . for now:
After I create a CCC backup onto an external HD, can any mac read the files (documents, pictures, music files etc...) from this HD (via Finder), or does that mac need CCC software installed to view the files?
yup, its not much different than just having a external hard drive that had everything copy and pasted using finder, its just better in the sense it can make the external bootable and its keeps it a exact match so if you delete a file on your internal it will remove it on the next "clone" from the backup