Thank you anon! I would like to say, I think you're right. I hadn't really noticed just how often he refers to Joan in his thoughts, but it's true that at this point he would be a lot less dependent on her, regardless of how much he still relies on her.
I will say that as far as him being less vulnerable, I think he's been a lot more so than in the past, but that it's always to a limited extent, something that canon seems to support. In the show, for example, you can see he's come a long way in opening up to others and allowing himself to let people in, but he's also mostly demonstrating this vulnerability around people he's come to consider "family" (Joan, Gregson, and Bell).
I also play him as being in denial about just how decent of a person he actually is and how much some people mean to him. The Sherlock I currently play cares for Kitty, but has yet to realize that he loves her despite making the analogy of him being her "father figure". He says that he's only ever loved three people in his life and names Joan, his mother, and "Irene." In Kiseki he's realized he loves Jamie for who she really is, not just for who he believed her to be, but in the show, he seems to be in denial about his feelings despite evidence to the contrary. I think the point where he truly begins to understand how important Kitty is to him is the episode where a man is interested in her, and he does everything in his power to keep her occupied so she doesn't get upset by the advances or potentially hurt. When Kitty tells him that what he did made her feel "protected and loved," there is a very noticeable shift in how he handles the situation, offering to take her and her date to an exhibit so that Kitty can be around the suitor while feeling safe. It's a very small, but telling gesture, something even Kitty seems pleasantly surprised with.
Sorry to vomit Sherlock feels and headcanons, let me get back to your points >>;;; I have been having him approach others when they're upset and try and have him comfort them in his own way while still not seeing how much he actually cares about them. With Art after the Bridge, he's giving him advice while wanting to maintain some distance lest Jamie decide to mess with him again. With Robin after Porthos leaves, he wants to reassure her while being hostess about the situation. In the Valentine post with Snow, its a combination of wanting to help while also knowing he may not be someone she wants to open with like say, her husband or children. All of these are people he's come to like, but again, he's not always good at understanding how deeply he can actually feel at times, but he'll get there!
But I'll try and be more clear about his vulnerability in the future, because it IS very much part of the new Sherlock and when I update him, you'll definitely see it more. Thank you once more for bringing this to my awareness as well as the Joan fixation. I will definitely try and be more attentive to these matters and work on them going forward ^^
I've been intending to have Sherlock find another person to bond with like he did with Miko and I do actually have two people in mind for that. Stiles and Real!Syaoran are the people I can see him taking under his wing, but I wanted to touch base with their muns first ^^;; I think JL and I agreed some time ago that there was some potential with Syaoran, so I'm going to keep up with their CR and see what happens.