Seems like a great idea to me. A few points come to mind for me. These may be easier said than done if it's based on a template, but hopefully there's a way to make some tweaks without too much trouble.
My main advice would be to try making the free 250-word sample edit more obvious. There's a chance that you get too many of them and it wouldn't scale well, but you could always downplay it if that happens. With a personal product like this, I'd be willing to bet that those sample edits would be a really powerful opportunity to make an impression.
I would also advise not hiding the navigation in a drop down menu, and I'd emphasize the "Meet our chief editor" part. With a service like this, that's a huge point. Making it clear that it's a personal service with direct interaction can be powerful. Seeing the real human, and your qualifications, behind a service like this is a pretty big trust signal.
Best of luck!