Yipe, I’m not even going to waste my virtual breath on the ignorant insults uttered in that first response. Clearly some message board denizens could benefit from having someone edit their words prior to hitting “submit.” Hmmm… maybe I should start a business called “Post Doctors.”
In any event, tnetennba (great name!) has the right of it, although what I believe Jinx is talking about is developmental editing. Freelance editing can run the gamut from proofreading to line editing to developmental editing. That said, someone who says “book doctor” is just using shorthand; I really wouldn’t judge anyone for using the title–it’s a marketing term, that’s all.
But to echo tnetennba’s point, it’s almost always new, unpublished authors who are petrified about having their work ripped off. Literally none of the published authors I know (including me) are concerned about editors or designers or anyone else at the production stage stealing their ideas. It just doesn’t happen, or at least it’s so rare as to be meaningless.
Yes, naturally plagiarism has occurred after publication (either by print or ebook), but I’ve almost never heard of it happening before.
Of course you’d want to enter into a contract with whomever you hire to help you with your work, so that should cover you. The thing is, though, I’m guessing that whatever evil-minded editor you fear–the hypothetical one who’s champing at the bit to steal your work–would have to rewrite everything anyway, assuming your ms. is that raw and unfinished.
In which case, s/he’s just taking your idea, which isn’t copyrightable anyway. Ideas ain’t worth jack on their own. Anyone can have an idea. It’s how you express it that matters.
In the end, Jinx, I really, really don’t think you have cause for concern.