^ Yes, it came true in a lame sort of way. He just travelled further into the future!
Nah, it was perfect. It's basically a better version of putting graffiti on the oldest wall in the universe that makes the time lords look like an army of fools for reading too much in what is actually a pretty benign prophecy. They had gone to mad extremes for nothing.
It was a waste of a good story though. The Doctor protects Gallifrey from an ancient prophecy of doom!!! Wow, can't wait!
No, he just travels ahead in the future and the prophecy comes true because the universe dies. Oh, and he mind wipes himself. But, not quite because he remembers a lot and then pieces together who Clara is at the end anyway.
Mr Awe