So I'm caught up until the Valentine's Day episode, and first thing I want to say is: I think we can confirm my theory about this being the dark, alterna verse where Holmes does not meet his Watson until after his canon cases. Lest it need be said: I am really, really enjoying this.
Part of what this show aims to do is show how much Holmes NEEDS Watson as a steadying influence in his life. Part of that is the evidence from the now- Sherlock flat-out tells her that she makes him a better detective, even though he doesn't know why. But part of that is from how badly things went in London- without her there. It's bit of a meta concept, really, but I do think it's intended. Without Watson, Holmes flounders. It's clear now, and it's clear then.
I'm also loving the honest-to-god character arc we're seeing with Sherlock. Here's a man who, in the beginning, was confident that he didn't need Joan. He didn't need the help with recovery, and he wasn't going to even try to do drugs again. In more recent episodes, we see Sherlock not only adjust to the knowledge that he needs help with staying sober- that it's a fight every day- but to the fact that he really does need Joan. He needs her companionship, her ability to call him out, and her strength.(Point of order: everybody needs somebody in their life who will call them out on bullshit and lend them a shoulder.)
At one point early in the series, we see that Holmes hates to be wrong, and hates when there's an outcome he doesn't expect. More than once he tries to tell Watson that he TOTALLY expected that outcome, he TOTALLY coached his kidnapper to text Joan in a way that would show Sherlock was being kidnapped. Joan completely calls him on this. In the Deductionist, he points out that the profiler has this same flaw, and at one point admits that he was wrong about the case.
I also love what we see happening with Joan: we know she's unhappy being a sober companion. She's doing it as a form of penance, and I believe she's very good at it. It's hard to admit you're miserable doing something you're good at, but I think the only real satisfaction she gets from her work is being proficient at it, and that the work itself gives her no actual joy. Being with Sherlock does- he challenges her in unexpected ways, he brings out the part of her that enjoys solving puzzles (I believe most of us have this in us) and he shows her new ways to look at the world around her. (Also, I love how Joan's Mom breaks this down and tells it to her.)
These changes in both characters lead up to the Valentine's Day episode "Details", when Sherlock reveals that he knows Joan has been lying about the extension, he knows why, and instead of being mad or regressing he seems to understand. He tells her in hesitating, halting sentences that he'd like for her to stay, he would make it possible for her to stay in whatever way suited her best ("you can stay in the brownstone. Or not."). He was as open as vulnerable as he's been so far- he wasn't sure that his gambit would work. Even though it seemed to be what Joan wanted, and the ideal way to solve both of their problems (she hates her real job and loves what she does with Sherlock, she gives him an edge and support that he doesn't otherwise have), it still may not work, and he put it out there anyway.
This is not just about her being his apprentice, but about how their relationship is mutually beneficial, and I think that's what moves Joan to accept.
Her acceptance wasn't assured, and I'm glad she made her own terms (including one where Sherlock continues to attend groups) before she'd accept it wholly.
Additionally, I'm happy that we were not introduced to Moriarty so early. We know he's going to be a Big Bad, but I'd really prefer if he were a Season 2 big bad, and it seems like things might lean that way. I think Sherlock (the series) blew their wad a little early with Moriarty (though I can see why they would do that), and I was worried Elementary would follow in those footsteps.
My favorite thing about this series is how emotional Sherlock is, especially compared to other depictions of him. I like that he is moved by the plight of those less fortunate, that he is genuinely distressed for the episode after Joan was endangered by the undercover DEA Agent. When he reveals the illegal immigrant status of an innocent woman, he is fucking haunted by the idea, and openly states it. The puzzle is important to him, and that is clear, but the people are ALSO important to him.
What I'd like to see: Alfredo! (I think I may be spelling it wrong.) I do believe we will see him again (after all, there's been no sign of Moriarty since the episode he was mentioned, and we know that's not the end of that) but because he's intended to take Joan's place after she's no longer Sherlock's sober companion, he hasn't been involved yet. I do want to see him get involved, now- Sherlock does need someone like him, and Alfredo is objectively awesome.
Joan going back into medicine- whether or not she becomes a surgeon again, I think that medicine is clearly a part of who she is and how she relates to the world. I don't think this will happen this season, but some tentative steps in the right direction would be wonderful. (Maybe she could consult! That would be thematically appropriate.)
More of Joan's family would also be nice.
What I don't want to see: I like Sherlock and Joan as friends, and I still DON'T want any 'will they/won't they' regarding a romantic relationship between them. I think a solid, platonic friendship between a man and a woman is refreshing and fun and I really enjoy their growing friendship.
I also don't want to see Moriarty for real this season, unless it's a teaser in the very last episode. (Like, his face is revealed then CUT TO BLACK would be acceptable to me.)
On a slightly silly note: Possibly my favorite thing on the show STILL is Joan's face when Sherlock says something phenomenally aggravating and/or frustrating. Lucy Liu is a woman of a thousand irritated eye rolls and I love her for it.