Most of the editors I've worked with have been dedicated, smart, and helpful. But my current editor was assigned the project and, among other things has asked for changes that totally diverted the text from the main story, sent me poorly written (ungrammatical) flap copy, galleys studded with major typos, and a proposed book design that was completely off-the-wall (and eventually changed). I've resisted where I could, rewritten the flap copy, and corrected the typos, but I have a sinking feeling about this project, which has not yet gone to print.
At this remove, it's hard to say for sure how much of this was the editor's fault. It's possible that (1) she's enormously overworked and her attention is divided (2) someone else wrote that flapcopy (3) you were sent a galley that had not yet been to the copyeditor (which is not uncommon, fyi) (4) and she finds herself at the mercy of equally overworked designers.
Or maybe she's incompetent. (This is not common among editors. At all. But it's possible.)
Is there anything I can do before the book actually is published? Like, ask to have someone else to look at the final result? Is there anything I could have done when I first noticed the problem? Can a writer ever ask for a project to be reassigned? Under no circumstances do I want to work with this person again. We are still onOh, that would be difficult. And awkward, and very probably unproductive. Editors are the head of their publishing team, and so to appeal for another set of editorial eyes, you'd have to go over her head. There are no lateral moves here.
friendly terms, but I'd like to send future manuscripts to someone else.
When the editor asked you for changes you disagreed with, you should have disagreed (perhaps you did). It's your story, of course.
Have you seen the book's development recently? You could ask your editor if you could see whatever is the most recent round, mentioning that the project has had a bit of a bumpy ride, and you'd just like to be sure you're being as involved as you can be.
As far as not working with this editor again: Don't send her anything. Submit to other publishers for a year or so, and then try other editors at the publisher we're talking about. There are different working dynamics at different publishers, so I can't say how possessive this editor is likely to be about you.
If (on the very unlikely chance) you sell another manuscript to this publisher and it gets handed off to that same editor, you could then speak to her superior about your concerns. That would have to be done delicately, however. If her superior has had other hints that things are not going as they should with that editor, your concerns may be given weight. But be careful of simply coming off as high-maintenance, or a complainer (an author type we do run into sometimes). Without corroborating evidence, her superior is going to side with her.
Some authors come into the business expecting their relationship with the publisher to be like their relationship with the customer service departments of other large companies. Certainly the customer is always right. But you aren't a customer. You're a contractor, and contractors are sometimes uninformed, unreliable, and unrealistic. If you look for someone to pull rank on your editor, remember—as far as the publishing company is concerned, you personally don't have any.
I do not get the impression that you are one of these people. Your positive past experience with other editors speaks well for you. And I'm sorry you're in this position. My best wishes for the book you're working on, and for your future success. If the editor is really as incompetent as she seems, she probably won't be in the industry for much longer.