Writers often want to know when to stop editing their work. You can over edit. The thing to keep in mind is that no matter how many edits you do, the publisher will always edit it more. Just make sure spelling, grammar and scene transitions are as near perfect as possible. Some publishers don't read very far if there are too many errors in this area. They are on a budget so too many errors translates to a big in-house editing bill to them. After all those in house editors get paid @ $150. per hour to edit.