Don't come knockin on my door for answers to any of these questions. I simply want to offer a thought that borders on such questions. I don't think a Nietzschean rhetoric would have to do with language in a reductive sense, limited to certain types of situations and answerable by specifically available topoi. Instead, I'm much more inclined to begin with rhetoric as a modus vivendi, Burke's equipment for living. But that does not prove them.
Life is no argument.
One of the critiques levelled at postmodernisms on occasion is its tendency to appear ahistorical and apolitical. Such a tendency is reprehensible, sayeth the left, because it ignores the specific contexts within which everything occurs. Deconstruction is an absolute critique of absolutism. Or, in Nietzsche's case, action is itself a reaction against reactionism. These are not all identical arguments, certainly, but they are analogous, I think.