The only editorial experience i have is on my own stuff (2 novels and a couple of dozen short stories). You can argue about the quality, but it is still a fair amount of words.
I have experience as a transcriber, so i have some professional experience with the written word.
Of course, I'm English, so my grammar and syntax will be slightly different, but not enough to cause too many arguments.
Tell me what you need, pass me a little bit of work, and we'll see if i can do what you want.