Yes, that was my understanding of the Catholic view. I have heard the term "separated brothers" used for some in Protestantism, which I take to mean that a heretic is better off (closer to the Catholic faith) than someone of a different faith altogether.
Since 20c Protestantism does not seem to even understand itself any more, I hesitate to apply the term to latter day Protestants. They are simply confused people, no comment on the present polite company.
Thank you, and yes, if Protestantism is defined as anything claiming to be Christian which is not Apostolic, then I would agree that such a group would be too far all over the place to be termed as one group. However, if we narrowed it to the Protestant Bible-believing Arminians and Calvinists with whom you regularly interact on FR, then maybe a case could be made for heresy? :)
May be. Why is it important to you?
Remember, aside from the technical meaning the word is used broadly. "Dumping the changed oil in the sewer is heretical".