Well, for me there is a discontinuity between religion in abrahamic sense and football, rock music, and even buddhism. While the former obviously covers what might be a kind of universal religious instinct, it does much much more. For instance, I don't think believing in God is the same as believing in the existence of ghosts, or in immaterial spirits. It should even be the same verb. A man of faith is not only believing in the existence of God, and that His words are in a Book, he is also his whole life a consequence of this belief. If you really believe in God, you should be working very hard to be a Saint. Every second of your life you are not climbing this path is a misstep.

In the Far East religions, you have most pieces of the jigsaw present: mysticism, the Sacred, priests, monks, prayers, meditation, afterlife, etc. But I think the central piece of a unique almighty exclusive God is missing, and then the result is completely different.

There is also this theory that the Far East did not have a powerful scientific revolution because of this missing piece: Without a God who created everything, there is less incentive to believe in a unique ordering of things (the Law of physics) and to try to discover it.

And no, Confucius is not a prophet, he made no miracles, he did not announce anything. He was just a failed political advisor who became the teacher of a few disciples. However, he proposed a very rational and revolutionary way of life, under the disguise of restoring the ancient Way. He also happen to be (along with Jesus and maybe Mohammad) the man who influenced the most the lives of most other humans.

Confucianism is a religion. No blurring out of technical theological details is required. Confucianism has a holy city, temples where people pray to him, miracles attributed to him, unquestionable holy books and an organization to promote itself. It doesn't lack anything that other religions have so it makes sense to call it a religion.

Not as a prophet, he wasn't said to have spoken the words of a divine force/entity.

Those are theological details.

http://en.wikipedia.org/wiki/Mandate_of_Heaven suggests some religious thinking