The cliffhanger honestly killed most of the suspense in this episode. When the ghost Doctor appeared, my first reaction was (as I noted before), "Oh, like we really believe he's dead." Then, since they had already mentioned that the ghosts were some kind of projection, it became pretty obvious that the Doctor was still alive somewhere and that the ghost Doctor is just a projection. And then a little ways into the episode, they mentioned the suspended animation chamber, and that clinched it. So, we already knew how he was going to get out of it.
The episode seemed to mostly be concerned with showcasing the bootstrap paradox, which is something that we've seen a number of times already in the series and the universe has not really cared about. Example: Exactly who came up with the idea of blowing up the TARDIS in "Time Crash"? And the Doctor has sent messages to himself in the past before. It was cool enough.
One of the things that bugged me was the whole "omg, the universe is going to explode if I change history and avert my death!" thing. Again. You know, after the whole Battle of Trenzalore thing just sort of disappeared and the entire end of the Time War was completely changed. I'm not saying that I object to either of these two plot developments (or that I don't), but it's kind of getting tired, especially since none of the horrible consequences the Time Lords fear ever come to fruition. However, for this episode, just like with season 6, it turns out that the death everyone "saw" didn't happen. Or perhaps it did, but the Doctor changed the history, and there were no consequences. I'm really not sure.
And then there's Clara. I'm sorry, but if someone says they're going to die, who responds by saying, "No, you're not going to die, because that would really hurt me, so you can't do that"? I honestly cannot connect with this character at all, and she poisons the rest of the episode.
The last thing that really bothered me was the Doctor's attitude that rather than saying "I'm going to save everyone", he's running on "I'm going to save Clara." I realize that, just like having a deaf character was simply a plot point so someone could read lips, this was said so that the Doctor, upon hearing the list of words, would be stimulated to try harder because Clara was the next person to die, but this is a more recent development in the character of the Doctor that I don't like. He's turned from the hero trying to save the world to a man with an obsession for one person.
So, you see, I really couldn't like the episode because it started with such a bad taste in my mouth and did nothing to sweeten it. Oh, I have one other question. If a person who can't hear is expecting to be attacked while walking down a corridor (especially by foes who can walk through walls), does she really simply face in one direction and never look behind her? Yeah... That's the kind of questions I was asking myself all the way through the episode. I'm not saying that I never used to question things like this in older episodes, but it just seems so common as of late.
Oh, one more question. Was the relationship between O'Donnell and the guy (don't remember his name) apparent at all before she died? Did I just completely miss it?