Regarding the title, while I agree it isn't all that important in the context of the episode, it's better from the context of the season. After all, I'm willing to bet most people who are even aware of the episode are people who have been eagerly anticipating the return and know it's title ahead of time. They're probably wondering what the Bells of St. John are referring to. Then, right at the beginning, they hear "the bells of St. John are ringing," which increases anticipation. When they see the TARDIS phone ring and the Doctor says "that's odd" right as they see St. John on the TARDIS, it reveals what it is. But, at that point, the mystery is supplanted by a different mystery.
It's a tease where they pull the rug from under you, yes, but it leads nicely to the other important things.