I wanted to delete some of my questions and answers that were not helpful to others. From my experience, I learned that I could not delete my answer if it had been accepted, and could not delete my question if it had been answered. With these safety features already in place, in case some crazy person decided to delete everything overnight, why can't I delete more than 5 of my own posts a day in a mass cleanup session if I wanted to?
I will be stealing this answer wholesale from Grace Note:
This is an abuse-prevention mechanism used to stop users from maliciously destroying a lot of their content in a short period of time and denying users access to it. It's intended behavior. Perhaps a bit over-eager in that department, but it's probably wiser to err on the side of caution for that.
I believe you're delete-blocked for the next week ♪ But past that, yes, it would probably be wiser to take a slower pace. You could flag for assistance, but if you have a huge backlog of things to be deleted, then it's probably a lot of ancient stuff that isn't going to be looked at any time soon, so there's no real need to rush.