I agree, in particular, on the part of language teaching. What I'd like to see is the possibility to see enhancements on tags, such as mass tagging to quickly provide more new metadata about sentences, so that users can easily find all the sentences with a given tag with the advanced search, and, by consequence, fetch more sentences regarding a specific grammar topic (I'm aware that some people, myself included, already tag sentences with grammar information, such as the verb tense). This would work also with quotes (the ones that comply with Tatoeba's licenses), since people, when contributing quotes, might want to have a quick way to provide the necessary attribution to the quotes they submit.
On dev, whenever I try to modify my settings, I get told every time that an error has occurred while saving the new settings, but no details are provided. No setting change is actually modified. I tested this with many different settings.
On prod, when one wants to delete one of his messages on the wall, he/she gets a confirmation box before actually deleting it. On dev, this doesn't happen, the message gets deleted right away without any confirmation box