Well, I can kinda see why people would frown on that f-word thing. I’m gay and I really don’t care, since words like that say far more about those who attempt to use them as bludgeons than about their intended targets. But lots of gay and not gay folks do care, and that’s fine, too.
Consider that in the American South, where I grew up, it was (and among some folks, sadly, still is) common to refer to Brazil nuts using a horrifically racist name. Thats what they’ve called those nuts for generations. But that’s no excuse for continuing to use such an ugly, freighted, hurtful word, is it? Of course not.
I look at it this way: the “pain” it costs me not to use a word even if it’s (so I believe, anyway) contextually correct and “harmless” is nothing at all compared to the pain hearing that word might cause someone else. That means I’m automatically a selfish, uncaring asshole if I choose to do it anyway, if I refuse to ever so mildly inconvenience myself to avoid harming others. The thing is, I don’t want to hurt people, even if I think maybe they’re a bit over sensitive (as so many are), so I choose my words with a bit of care and empathy. It’s honestly not at all inconvenient unless such language makes up an inordinate amount of your daily vocabulary.
As for fanfic writers taking liberties with characters, I don’t see why it matters. The instant someone takes hold of another writer’s character without permission the foul deed is done.
Whether they try to stay true to the character or not seems totally irrelevant. All unauthorized fanfic is essentially an assault on someone else’s creation. It’s theft by its very nature.
That said, as long as they’re not making money off it and it’s clearly marked as fanfic and understood by its readers to be unaffiliated with the original author, so what?
What has actually been stolen or lost? Nothing. That black lesbian Gandalf over there is clearly not a Tolkien creation, and probably not something he’d approve of, but so what? If writing about her makes someone happy and reading about her makes someone else happy, why on earth should anyone who doesn’t fall into one of those two groups care even a little bit? Just let them have their fun and don’t read it. Nobody’s forcing it on you. There are plenty more stories where that one came from, after all, so find one that suits your fancy. Life’s too short to spend it being offended over such silliness.
Characters aren’t real. They’re amorphous even canonically, because they’re just words being interpreted by a brain and no two of us will interpret the words a character is made of in the same way.
They’re whatever we decide they are.