Currently, when you export content, it is very unclear what you are exporting. Once you have done so, there is no way of knowing what is in the file until you import it to another class, and even then it's not obvious what happened. Moreover, when you import, it automatically overwrites anything that matches, without any confirmation or list of what.
When moving some assignments from one class to another I accidently exported more than I meant to (at least, I assume that's what happened). When I imported into the other class, all the assignments and questions got altered, including the ones the students were working on (it removed the restriction on how many attempts they could have at the homework!). There is also no obvious way of undoing these changes in one go.