I think the problem isn't that you're addressing the whole "slavery" thing, so much as making it a big part of her story. It's more than a little unbelievable that you and Lin are going to change history, not to mention a bit much for the focus of the game: a harem hotel.
I don't mean to be overly critical, but the story with Lin makes me want to approach it less because it gets to be a little overwhelming, when I'd rather just focus on her individual life and not the lives of every single elf in the game and how we can save them.
I mean this is a game where you're basically just getting your rocks off with every grown woman that walks into the hotel, it just seems like the focus should be a little less... revolutionary.