So the "Powered by. . . " is termed a copyright notice?
Is this part editable then: "Click here for Live Help - "
The "Powered by Help Center Live" text is indeed a (somewhat informal) copyright notice. It simply identifies to your users that you are using technology developed by the Help Center Live team and that the technology is not your own.
Anything before the "-" in the statement "Click here for Live Help - Powered by Help Center Live" near line 104 in the language file should be modifiable without violating the terms.