My suggestion is slightly different than Amire's. In my opinion, the translating tool should just be a mode of the visual editor (that is what I meant by merging). I don't think there is a point sepearting those two features: translating is just one method, of many, to write or rewrite an article. In CX, there is quite a strict editing limitation: You can not add your own paragraphs, for example. The limitations are not neccesary, but various features such as side-by-side view, quick image and paragraph addition will be very useful when creating or editing an article.
Another aspect: In CX's current form, there are two types of articles: those who are saved as a translating tool draft, and normal articles. I think translated articles should be treated just like normal articles: when editing them, there should be a translating option. It does not have to be exactly in its current form.