1. There is nothing quite so infuriating as an author who ever-so-slightly misquotes (or deliberately alters her quotations, take your pick) every single time.
2. On a more serious note, sitting around doing footnotes forces you to think really carefully about the interpretive vs. factual footnote question: do you nudge readers in a particular direction, or do you engage in your best Sgt. Friday impersonation? For example: "nudge" readers about one character's academic career (which zigged when it ought to have zagged), or just explain Oxford academic titles for the benefit of US readers and let everyone draw their own conclusions? I started out nudging, but in the process of editing, I've been going in the other direction.
3. Idiosyncratic translations, also really annoying. I read French fluently, and yet, for the life of me, I cannot link one lengthy quotation to anything in the original book. (Then again, the previous editors just left it alone, which suggests that others have experienced similar frustrations.)
4. There's a part of me that wants to footnote the footnotes, so to speak, and yet there's no room.
5. "May you spend eternity annotating Squire Wendover's library" is my new go-to curse, followed closely by "May you spend eternity annotating one of Robert Elsmere's dinner parties."
6. I probably need to edit out the quotations and just leave the source references (will anyone really read that chunk of T. H. Green hanging out at the bottom of the page?).
7. Of course, then there are the quotations that just don't seem to exist anywhere. Plus the invented titles for books, paintings, and poems.
8. One of the great difficulties with footnoting Robert Elsmere is that Mrs. Ward produces her reality effects by tossing off contemporary high culture references. Nobody recognizes any of the allusions now, of course, but they're integral to the world-building.
9. Solving an editorial problem is pretty fun.
10. I think that there are some accidental zombies lurking in Squire Wendover's library, although the wording is ambiguous enough that maybe Mrs. Ward gets away scot-free.