Button in sentence translation to quickly indicate no translation required
When you're doing translations, often there are phrases that require no translation: names, places, URLs, punctuation marks incorrectly identified as phrases, numbers, and so on. Instead of having to copy and paste what is already there (or people make typos), there should just be a button near the translation box to click if you think that the sentence does not require translation (this could show up conditionally, depending on an algorithm that analyses the phrase).
Additionally I think it would be useful to have a button to flag errors like punctuation and URLs showing up as separate sentences to translate.
Finally there should be a report this page button to click if you think there's something inappropriate on the translation (more automated than regular feedback box)