I enjoyed the fact that you replied to these claims without having to argue about the poetical beauty of the Koran.
I'd add that one could argue that the Koran is a beautiful piece of literature and still think it is not the word of a god. Also, I'd say that it is not true that for someone to experience a literally work he needs to learn the language. If that was the case, than Shakespeare wouldn't be famous among Spanish, Cervantes wouldn't have English fans and Homer would be long forgotten.
Let's consider Homer. There are Greeks today, but their language is not that of Homer. Languages change over time. You may learn ancient Greek, that is true, but you'll never know for sure the context, the idiomatic expressions, the subtleties of the ancient Greek. Not even if you are a Greek.
Thus, would it be true that only Arabic speakers can grasp the miracle of the Koran, than it would also be true that it is not the modern Arab, but the Arab of the time that matters, including the context and all idiomatic expressions.