The theory of Olver being Gaidal Cain is interesting, but for it to be true one of two things needs to happen. 1) At the current timespan the books seem to cover (I judge it to be about 2 years at this point), the series would have to go on for MANY more books before Olver is old enough to do any good. 2) Olver would have to get old real fast. Of course with all the ter'angreal lying around, maybe that's not impossible.