I thought this episode got off to a good start with some funny scenes, e.g. when the Doctor met Clara's family and only mentioned later that they couldn't see his clothes. Mind you, if she was trying to persuade her family that she had a boyfriend, introducing him as "The Doctor" may not be the most convincing approach; it would probably be better to use his standard pseudonym (i.e. John Smith). I also liked the idea of using a time machine for a completely mundane goal, i.e. cooking your dinner.
Going back to Day of the Moon, the Doctor tricked one of The Silence into saying "You should kill us all on sight" on camera, then embedded that video into the footage from the Apollo moon landing. That way, everyone would see that clip, and remember it if they encountered The Silence again. That was a clever idea, although I do wonder how it would work out in practice. For one thing, it assumes that people would be physically capable of doing it, i.e. that they'd be strong/fast/skilled enough to win a fight. Also, I assume that they still wouldn't remember it afterwards.
One of the creepy ideas about The Silence is that I can easily imagine them (or something similar) existing in our world. There have been several times when I've been alone in a building and heard the floorboards creaking, but when I've gone to look nobody has been there, so I've just dismissed it as "the house settling". According to this theory, there was someone there, but I forgot about them as soon as I turned around and they were still there, watching me.
So, how would that work after the Apollo clip? Here's a scenario: you're standing in the kitchen, making a cup of tea, then you turn around to get some milk from the fridge. The next thing you know, you're panting, your heart is hammering against your chest, and all your limbs ache, as if you'd just been sprinting. Also, you're clutching a breadknife and you're covered in blood, although you don't know whether it's yours or someone else's. Would you just continue making your tea or would you panic? I realise that may be a bit too dark for a family TV show like Doctor Who, but at the very least I'd expect Clara to recognise The Silence when she saw them in this episode.
I also liked this idea:
Dr Who episode idea, when cats stare at nothing, it's actually The Silence, and cats can remember them.— Bethany Black (@BethanyBlack) December 27, 2013
When the Doctor and Clara went down to the planet, they discovered that the settlement had a truth field around it, which was coming through a crack in the universe. That's a valid premise, although I'd argue that withholding information doesn't necessarily count as lying. Think about giving evidence in court when you're under oath: you swear to tell the truth, but that doesn't mean you need to recite a list of every film you've ever watched. Still, maybe the Doctor and Clara were initially blurting things out because they weren't used to it. The bigger problem is that they lied to each other later, while standing in the field (having a fake argument).
It then turned out that Gallifrey was on the other side of the crack, broadcasting a message through it: "Doctor Who?" This goes back to The Wedding of River Song (which I also re-watched a few days ago). In that episode, Dorium Maldovar said: "It's all still waiting for you. The fields of Trensilore, the fall of the eleventh, and the question. The first question. The question that must never be answered. Hidden in plain sight! The question you've been running from all your life. Doctor Who? Doctor Who? Doctor Who!"
However, I thought that they'd already addressed all those points in The Name of the Doctor. The Doctor went to Trensilore (where he was doomed to be buried), and by revealing his name he gave the Great Intelligence access to the TARDIS, which then allowed the GI to jump inside his personal history and undo everything. It turned out that this planet was also Trensilore (at an earlier point in its history), but repeating the same concept here felt like going back to the well too many times.
More specifically, the Doctor said that if he spoke his name then the rest of Gallifrey would know that they'd got the right place (maybe they've been trying several alternate universes trying to find the right one?) and that it was safe for them to come back. If they want him to authenticate himself by saying something that only he knows then that's fair enough, although it would rely on them also knowing his real name, in which case it's less of a secret. However, if they're relying on the truth field to make sure that he tells them his real name (because they don't already know it) then why are they asking that specific question? Wouldn't it be better to ask him explicitly whether it was safe? After all, he already had to use the Great Seal to decode their message in the first place, so surely that gives some indication that they've found the right universe. For that matter, he could truthfully tell them his name even if it's not safe for them to come back: he explicitly threatened to do that later, i.e. if the Daleks shot him then he'd summon Gallifrey with his dying breath.
This led to a standoff: if the Doctor left then the various ships in orbit would burn the planet to stop the Timelords coming through. At the same time, they couldn't launch an all-out attack while he was there, in case he answered the question to bring the others back. However, I'm not convinced that this works. For one thing, the episode later showed that the people on Gallifrey were capable of opening up a new crack in space, and presumably they would always have had to do that to bring the planet through, unless the billions of people living there wanted to queue up to walk through the crack on Trensilore in single file. So, burning Trensilore wouldn't actually stop Gallifrey. Maybe it was supposed to be a hostage situation, but the ships in orbit didn't want the Doctor to stay! Also, the Doctor explicitly said that the crack was in the universe, not in the wall. This implies that even if someone knocked down the wall, the crack would still be there, and I assume that the same applies to the whole planet. If this signal was being broadcast throughout the whole of time and space, presumably the Doctor could answer it from anywhere, so he didn't need to stand next to it.
For that matter, why didn't the Doctor answer the question? I can understand him not wanting to restart the Time War, but Tasha Lem explicitly said that the situation turned into a war after the Daleks landed, so how would it be any worse? Things should be different to last time, since there are the same number of Timelords but far fewer Daleks. Also, why didn't the Doctor or the religious order evacuate the settlement? It seems as if it was fairly small (I think they called it a hamlet) so I'm sure there would be room for everyone inside the TARDIS.
Speaking of the Time War, the Doctor aged 300 years over the early part of this episode while still looking recognisable, then he aged a few more centuries after that. So, how long was the War Doctor (as played by John Hurt) fighting the Time War, if he also aged visibly? The 10th Doctor (as played by David Tennant) said that he was 900 years old, and maybe the War Doctor accounts for most of that time?
As a random nitpick, the Doctor spent a lot of time at the top of the bell tower while the big bell was ringing. Trust me on this, you really wouldn't want to stand that close without ear protection! (See my comments on climbing Big Ben for more info.)
Again, there were some good concepts in here. I liked the wooden Cyberman, and I don't mind a quieter episode where the characters reflect on mortality. It's just unfortunate that taken as a whole, it doesn't really work.