I liked when Sherlock said "that's why he stays" and John had a tiny smile.  Then the same when John said middle child that explains a lot and Sherlock had the same tiny smile.

So did the parents of Victor never search for their missing child?   Eurus was never punished for killing a kid and setting the house on fire?   And all she needed to stop killing was a hug? Terrible story telling.  What would they have done to the person if it wasn't a sister???    I hated 90% of it.  And Moffet says he thinks Molly was 'ok' with Sherlock making her say I love you and not bothered by it.  Of course she looked happy enough at the end to come babysit.   Only some furniture and walls scorched by the 'bomb'.  I did like that part of them cleaning up and having grown more baby.  Sherlock and John looked very happy.

If the entire episode was Sherlock’s plan he could not have been as high as he appeared in some scenes or he has a really big tolerance for whatever drug he was on to be able to function.   And if he did plan it all let me break it down as I understand -
Two weeks ago he told Mrs Hudson and Molly to be X place.  I think he told both of them his plan.  I also think he told Molly to tell John he was in worse shape than he was.  
I still don’t buy that Sherlock could deduce the therapist and date and time John would get an appointment (2 weeks in advance) as  John said he had just decided that week to go.   Still going with the improbable that Sherlock still could deduce all this – how did the sister (I don’t think her real name is Eurus) know John would go to that therapist that day to kill her and take her place?
And blah blah he deduced,  Smith could have smothered him before John got there.  But the power of TV he got there in time.   And knowing John’s pent up anger issues (since John was willing to punch him around before)  he guessed that John would do some damage so he’d be hospitalized (don’t know if I believe he had the kidney damages etc that Molly said – she does examine dead bodies as Mrs Hudson said)  he is hospitalized.  And Mrs Hudson is the one that pointed John to where the dvd was – so she had to know the plan.
But he didn’t know that he saw a fake Faith so he had to be really thrown when the real one showed up so I am not sure how having her there figured in the plan but TV wise it was only so he would see that the woman he talked to was fake.
I don’t like the secret sister idea.  It’s cheap writing IMO.  It could easily have been (and probably is) a Moriarty helper.   So it didn’t have to be a sister.  
I think Billy helped him ‘play’ the part as drug addict without it getting out of control.  I do not doubt he took drugs, as he seems to do easily.   As we have already seen with Magnussen.
I do

I am not liking this season at all.  I didn't like this episode.  I have a lot to comment on but of course left it at home (I am at work).  But I'll ask some questions.  why did Mrs Hudson call Mycroft a reptile when all he was doing was clearing out Sherlock's drug stuff and trying to find him?   Sherlock is smart but I don't think he can plan what is going to happen in 2 weeks time.  Did he get Molly to just say he was that ill or was he really?  Did he have Billy- aka Mr White- giving him low dose drugs so he would appear under the influence so he could then act crazier?  What made this Smith guy the worse bad guy they have had?  I think Moriarty was worse.   I agree that the sister (which I think is a stupid idea) had been working with Moriarty but I don't think she actually shot John.  John's anger was too much especially if he believed Sherlock was high,  how could he have defended himself but then it was all part of Sherlock's stupid plan. 
I love Mrs Hudson.  She was the only good part of this episode.  And I liked Billy too.

I didn't like this episode even after watching again. 
I didn't like how Sherlock acted when they were reviewing the video they had changed to save him.  Plus all his manic acting and the continuous texting through the entire episode.
Sherlock and John's characters were completely different.
Didn't like Mary being in every case they were on, especially that they had to have her on the phone and in video at the crime scene with the boy.
Too convenient that the kid who died happened to have a Thatcher bust broken and why would Sherlock care??
Dog - what a wasted bit of time.
John's flirting.  I think the woman has insinuated herself into his life for some reason but did they have to go with him cheating on Mary?  I think it was more than texting.
All the 'watery' stuff they did.
If Sherlock was hiding in the last house with the statute with police waiting, why did the fight go on so long?  Didn't the police see the guy enter?  More wasted time.
I think Benedict and Martin are bored with these roles.  IMHO