Anvilicious: "There are always choices." The theme about survival and overcoming addiction in Ink Exchange as well. These are arguably examples of Tropes Are Tools.
Fan Community Nickname: Lovelies. Members of the fan forum are Rathers. Yes, it does lead to jokes about being 'rather lovely'.
Foe Yay Shipping: Some in the fandom ship together Bananach/Niall.
Heartwarming Moments: When Niall forgives Irial. Actually, the entire second half of Stopping Time. And pretty much any other Nirial moment.
Moral Event Horizon: Bananach crosses it in Radiant Shadows, when she kills Tish.
Nightmare Fuel: What you get when you think too hard about the Dark Court's activities in Ink Exchange.
Bananach is also a source.
No Yay: Think too much about how Beira acts towards Donia in the first book and you could be squicked out.