The JWs generally teach the idea that you are your data. They dont like it, of course, when pressed because of exactly the problems outliend in the OP. Identity is generally thought to rely in some way on uniqueness or numerical distinction and, obviously, we can put my data into any number of places.
The great advantage is that it allows the JW idea that people can be raised as either human or else non-human. The cost is merely in the absurdity of identifying the person with his data. JWs would be far better off simply being substance dualists, identifying the person with an immaterial soul -- then it wouldn't matter if you were a human or a spirit. But JWs hate anything that smacks of philosophy, especially if it's Greek.