Hi again Pat,
You're not the only person wanting to remove "Whole forum" from the gradebook item, as the problem has been reported as MDL-70379!
As I mentioned in a comment in the issue, please note that any language string changes will only take effect when you create a new forum. For an existing forum, you need to go to the forum settings page and save changes.
Also, for anyone browsing this discussion, please note that the English language strings gradeitemnameforrating and gradeitemnameforwholeforum are going to be improved so that the name of the forum comes before the words 'whole forum grade' e.g. Neutrino Discussion whole forum grade.