It would be nice to have an easy possibility to find out what translations you've got your ups and downs for, so you can see what people liked/disliked?
What do you think of a place where you could submit tentative translations to? That would be fun for those of us who are still learning. Sometimes I'd just give it a try, but I'm really not sure if this is really correct. Or you'd translate most of it, but you are missing one or two little bits and pieces. You don't really want to be punished by a tsunami of downs, but it would make a nice exercise. Some of these Chinese phrases look soooo tempting!
That is a good idea. For now you can just submit translations (even if they are not finished), and mention that it is not finished. I'm sure the community will not punish for it :)
When you've finished a translation, it would be nice to have a link to the list of pending translation requests to be able to continue your work, maybe next to the existing "back" link that brings you back to what you've just finished.