Before ranting and bitching about Jim Moriarty, please read these stories: The Final Problem and The Adventure of the Empty House. And remember, Moffat and Gatiss are updating (even mixing) the Sherlock Holmes stories, not everything is a product of their brilliant minds.
The same goes for John getting married and leaving Baker Street.
Steven Moffat in his interview at Paris ComicCon
If you had a TARDIS, when and where would you go?
Oh, I dunno. Everyone else in the world has a better answer than me right now. Never ask a happy man where he wants to go, i just don't really want to go anywhere.
Maybe I would take some Sherlock DVDs back to Sir Arthur Conan Doyle and see what he thinks.
He'd probably punch me.