(#3)that would be very time-consuming.Scratch Team will review the post. And if it's an invalid reason to delete, then Scratch Team will put it back and give the deleter an alert. So, this would be allowing people to be deleting posts that give cons to a suggestion, or deleting posts that link to the original of a duplicate topic.
also this would often be used to delete rude posts, which should be reported instead so ST can alert the user.