I'm the same. I guess I'm kind of religious about canon, especially with something that is still current. I will rarely look at official spin-offs, and almost never at fan fiction.
I don't have any strong objection to it, though. I see it as a harmless sideshow. If that's what you want, go for it. A couple of people at my writers' group do or did write fan fiction. I imagine it's a great way to get people to read your stuff, when you're an unknown writer. Maybe I should try it. (Hmm,
50 Shades of Grey's Anatomy?
)
Lawsuits are incredibly unlikely. They'd cost a lot of money, for little return. A C&D is much cheaper, for the same result. That doesn't mean it's not illegal, or the C&D wouldn't work either.
When I was playing with my Star Wars figures as a kid, was I making up stories about the Star Wars characters, and sharing them with my friends? Yes, I guess so. (Although mostly not, actually. Any figures would probably have done. The power of marketing on young impressionable minds.) At the time, I couldn't really have spread them any further if I'd wanted to. The internet has kind of changed the definition of "publishing". In a sense, you are still just sharing with friends, it's just that anyone in the world can come along and take a look.