Sherlock is back from his hiatus and as promised, has been canon updated. But I am adding this because considering the kind of character he is, I think it's important we cover all the bases.
Sherlock is not an evil person, BUT he isn't good at filtering his thoughts and being"nice" to people. He observes people for a living. He sees them as riddles. That's his job. So things your characters may not want him to see or notice, he usually will, and might even "solve" them. When he does, he pretty much comes right out and says so most of the time, and in canon it's gotten him into trouble. Also his job involves a lot of triggering and disturbing cases (murder being the most prominent), and he's frank and open about discussing them. He's also a former drug addict and often meets and interacts with characters from his world who may have histories with addiction, trauma,and/ or different kinds of abuse.
SO.
This post, much like JL's Pan post, is for everyone's benefit.Please check it out and please feel free to comment and respond to the questions there. Any additional inquiries and concerns can also be addressed there or on plurk ^^