The idea sounds quite interesting. A couple of things to consider though.
Rather than have a High Aspect of "Wereraven Librarian", how does: "Bookish Scion of Huginn/Muninn" sound? The Huginn or Muninn depending on whether one is descended from "Thought/Mind" aka hugr, or "Memory" aka munr. To my way of thinking, for someone as interested in books and collecting/keeping lore, then being descended from Memory would seem more apropros, but that is just my own personal opinion.
By having Scion in the High Aspect, that establishes ones relationship to one of Odin's Ravens, as well as providing a potential explanation for how/why one might occassionally suddenly start having feathers. It also leaves plenty of room for hooks to any, every and all sorts of shenanigans that various Nordic groups might get into, or have been involved in. And would explain why statuescue blond-haired, blue-eyed "women" might sometimes stop by and check the character out.
For the Trouble Aspect "Self-loathing Shifter" would work. If one were willing to have a bit less (conscious) control over when/how one shifted between raven and human forms, then a Trouble Aspect which might work would be something like "Ignorant of the Family Conspiracy..." which can establish some lack of knowledge of what is going on, familial connections, secrets kept as well as links to ravens.
Definately interested in seeing/reading more about the character and his (mis)adventures.