I think you missed the point of Phantom Stranger. He had to deliver Rachel to the people who could train her in her abilities. The only people who could do this are her father and his minions. If this doesnt occur she will never become Raven and be strong enough to stand against him when the time comes. Rachel would have just been a tortured young girl unable to control her ability wandering the Earth feeling only pain. Now that would have been evil.
I was more interested in this family he had at the end of the story. Are they figments of his mind or some real family he has in an effort to find some happiness? Will their deaths make him even more a stranger? I am looking forward to finding out.
And if time moves faster where she is, then she could be in the Teen Titans sooner rather than later.