I was so busy with stuff, I can only answer now. But you already pointed out so many things! I can only agree with most of it, though I couldn't read everything. Four topic pages of very long, very good posts!
First of all, thank you
Jd! I agree with nearly everything you said.
So... Forget every episode you thought was the worst and most misguided in this series' history. Nothing will ever come close to how far this single episode, this finale, has departed from where this all began.
Oh, Yes! But I shall come back to that in a few... or several... or some lines.
[spoiler]
What I always liked about the Holmes canon was that sort of in-between: the things that are purely left to imagination but never outright shown. When we show these things and really focus on them, we inevitably close that gap. I think a great deal of the fascination that's surrounded Holmes and Watson all these years is that we really don't know everything about them and their interactions. How they handled certain things and how certain things unfolded are and forever will be inherent mysteries left purely up to the readers to solve, all with their own conclusions. Here, we're spending a lot of time establishing those moments that... I really can't help feel would be better off minimized if not left off-screen entirely. It's like they're spending 80% of the episodes just to have fun, silly, touching moments between Sherlock and John, and trying to find a way to throw in a case at the end so that it still at least appears like a mystery series.
[/spoiler]
^ I totally agree. Not telling about everything, was really a good thing. But to be honest, I think you give Doyle too much of a credit. Holmes sacrificing himself in a duel, yes, that's what we think now. Tbh, I doubt Doyle had that in mind. I think he decided on this by chance, because subconsciously he knew Holmes would act in this kind of way.
As there is a lot of daily life and interaction between them, is why the episode is funny at first, but then you don't really feel like watching it again, by which I agree with
Mangaluva.
@Patrick: Yes, there was always some fan-service, but it was limited. It started in the first episode, when Mycroft said as a joke that Holmes and Watson might marry end of the week. But in the third season it tipped from "let's spice it a little" to "let's turn the whole thing into an episode" (referring here to episode 2, although episode 3.1. had already too much of fan-service). That's the problem.
Now about the gay topic: Seriously? In what kind of world do we live that between "I don't care about the person" and "I want sex with that person" is nothing in between? O.o There are asexual people out there and to say "this is not possible" is such a discrimination! Holmes is asexual. “I'm a brain, Watson. The rest of me is a mere appendix.” is the quote I would like to give at this point. And why do we have to change this fact about Holmes? (This is really something that is special about him and personally I like it a lot. It wouldn't be Holmes otherwise.) Just because you are asexual does
n't mean you have no emotions.
I'm not asexual, but I can say from my own experience that you can really be good friends with someone without starting a sexual relationship. I think it is sad that some people (I don't say names here), don't understand this. I feel a little sorry for them, tbh.
Okay, but enough about the general thing.
I can hardly add something to your discussion, as you said most of it, but... (this wouldn't be the internet and not me, if I was not to add something

)
[spoiler]The idea of the episode was good, but Moffat just cannot stick with "let's do a good episode" he always wants to overdrive things. And then stuff gets horrible. Episode 3.2. nearly had no story, then episode 3.3 had far to much. They could have split it up. I thought, when John nearly died in 3.1, that this is the way they wanted to go. Always something little happen... a little more. So that Holmes really gets pissed. Like in the story "The three Garrideps" (I think it was), when Watson was nearly killed and Holmes was about to shoot the criminal. But that was
on impulse; a completely different situation to the one in 3.3.
One of my thoughts was "this is not only 2010 but 1998".
Because in 3.1 Sherlock said "Killing me is so 2010" and then he nearly-died and most-certainly-died in 3.3. 1998 is referred to "The Avengers" (no, not the Marvel Comics, but with John Steed and Emma Peel), I mean, even the name August is the same. And to be honest, I totally lost the point in all this. Perhaps you can help me here. Mycroft says Magnussen was too intelligent to interact with governments, but wasn't that exactly what he did all the time? And why shouldn't Sherlock interact and should have his own brother as his enemy, if Magnussen himself said he never had Mycroft in his hands? Is it just me, or is this whole episode based on a HUGE logic mistake? You complain about Holmes being a weak character here, I think Magnussen himself is an incredible weak character. For me he isn't actually a character, just some very bad behaviour personalised so that everyone dislikes him. Where is the motive for all of this? (To have Mycroft in his hands... but WHY??? To see them dance? The Danish Joker or what?)
Holmes using a woman to this point of few: Are you making fun of me? Perhaps that's me, but somehow this doesn't fit in my personal picture of Holmes (or Sherlock).
How they should have done it: The idea is good, then throw some motive in it (I mean, it would make the criminal interesting). Don't kill Holmes, but let the criminal have some issue with Mycroft for example (the one no one can touch, but then someone actually gets his hands on him), but not now, more like in the fourth season. They knew they would get a fourth season from the beginning after all. Then just introduce Magnussen in 3.3 during a case... an actual case, just like usual. And then later on refer to it. (It has to be different than 1.3 and the Moriarty plot.) Perhaps a case in which we see in the end that Mary is not the innocent nurse we thought she was, which could have left some awesome speculations that lead into the fourth season. (Then of course: Don't make Sherlock have a gf.)
And... DON'T BRING MORIARTY BACK! I mean, I love this dude and I was so sad that he was dead. But... LOGIC LACK AGAIN! Yes, you can explain everything, because this is fiction, but... either everything that follows has no point or the whole second season is pointless. The only thing how they can save the situation (as no one died although Sherlock is back, but Moriarty is not dead and Mycroft and Sherlock not seeing this, although they were so intelligent to figure out Moriarty's plans, but then they were not and... okay, I stop here) is to turn Moriarty into a Joker. And... that's so 2008.
Yes, I can cope only with this situation with sarcasm and cynicism, I'm sorry. Well, actually I'm not.[/spoiler]
This is just additionally, many other things were named by you already. And I calm down now.
