Back on the editor thing; in their need to fix it, I think it's important they don't edit your voice out of the book. Our voice, or character voice, is one of the few things we have going for us.
I write in first present, so I use comma splices all the time, because that's how people think, in bits and streams and fragments. Writers often forget that when they're writing first present, the prose is unvarnished and immediate character development. Conforming the whole lot to CMoS would...well...pretty much suck. This is why getting the right editor is so important, otherwise they end up doing more harm than good.
Also also, punctuation was originally intended as a shorthand, like music notation, to let the orator know how to read the text aloud. This is how I use it. If I want the reader to pause and reflect, they're getting a comma, regardless of grammar
rules suggestions. Not to be snarky, but my books are not junior high English papers. Fortunately, I don't have to make a marketing department happy either.
I think one of the major stumbling blocks for writers is trying to conform to this notion of what a story is and how it should be written. As a rule, I think writing advice is pretty much horsesh*t. There's an exception to everything, really good ones too. This desire to follow the rules shows up most frequently as stilted prose, lacking rhythm and personality. There's nothing wrong with it, grammatically speaking, it's just boring to read. It's okay to take risks. I think that's how we find our voice. Besides, we can always fix it in the edit/rewrite..
.or not?For example, one of my characters always mixes up number agreement when using contractions.
'There are' is always reduced to
'there's'. It's grammatically wrong, but people say it all of the time, so it feels authentic. One of the best ways to differentiate characters is to have them break the rules in their own special way, especially if there's a reason for it. (There should definitely be a reason for it.) Loosen the tie and let your characters breathe, er...dance.