It was a horrible hand wave. It sorta didn't explain why the Silents needed to take over the entire Earth.
And why would that need any more explanation than it had already gotten long before this? They were trying to create a fixed point in time, which is not an easy thing to do and requires all kinds of convoluted maneuverings to which we are not privy and probably could never understand. Basically, it's a "wibbly-wobbly timey-wimey" thing and that's all we need to know. That none of this was rehashed here is a GOOD thing, because that story was already done and this was a new one.
Handwaving is a fundamental part of storytelling in
Doctor Who. It has been since the beginning. There have been times when nearly every episode began with a handwave to dispel the last scene of the previous one. This flippant fickleness is part of the fun and the endearing charm of the show. The writing is very aware of itself, its conceits and its conventions. If this bothers you...I guess you could stop watching the show, because, I'm sorry, you will continue to be extremely disappointed by it.
I guess you could stop reading the internet, because, I'm sorry, this episode was EXTREMELY disappointing. And not satisfying for me at all. It was a lot of telling. Not a lot of showing. And the Doctor was... not The Doctor in this story. He was a passive character. In his own finale. He didn't try and find any solution other than just stay put and keep doing the same thing for 900 years. He gave up. That's not the Doctor.
He didn't give up. He decided to devote the rest of his last remaining life to protect a town of innocents from being obliterated by a situation he himself unwittingly created in the first place. (And by extension, the rest of the universe, which surely would be devastated should the Time War begin anew.) It's called character development. The Doctor had spent all his lives running, tricking his way out of predicaments, and finally stopped and accepted this responsibility when faced with it. He was absolutely the Doctor, the "good man."
I think what needed to be shown was, and what needed to be told was. Let's remember that they only had one hour to do this story in. Can't show
or tell everything, and again,
why would you want them to anyway?
...the fact that this was never written as his last regeneration prior to this episode, with at least 4 different episodes contradicting that fact...
People were speculating this was actually his last life for some time before this episode. In the gap between the 50th anniversary and it, I did a marathon of all Matt Smith's episodes to see if anything precluded this interpretation. Nothing did. To my recollection, for every occasion when the idea of regeneration was raised, there is a fairly straightforward reason why it is not a contradiction:
"The Impossible Astronaut" - it wasn't really the Doctor, it was the
Tesselecta putting on a show
"Let's Kill Hitler" - "regeneration disabled" (this phrase accurately describes the condition of having exhausted one's regenerations)
"The Angels Take Manhattan" - the small amount of energy he used to heal River's wrist can be presumed to be left over from when River gave the remainder of her
own regeneration energy to heal him in "Let's Kill Hitler"; it may very well have been all that was left and if there was any more he could easily have used that up somewhere along the line at Trenzalore or elsewhere
"Nightmare In Silver" - it's a bluff
Those are the only ones I remember; are there any more?
Oh, and after refreshing my memory I found the answer to my own pedantic complaint about the holographic clothes: the "hologram shells" had "heat loss filters." Simple enough.