As to chapters and episodes, while a few oddities exist, most have been covered and even retold in digest format. So again, possible new articles should be vetted by admins.
While some articles will be much shorter than others, stubs are discouraged. We have an entire article devoted to characters who have little or no impact in their appearances, and things like "Jerk who pushes Kaede over at the carnival before slaughter" belong there and not in their own article.
Please do not base edits of characters and events on your own biases or sympathies for the plight of the characters. While it would be nice to think Bando or Lucy did away with Mayu's parents, no evidence exists for that.
The door is always open, but your work will be checked, and, in extreme cases, bans issued for repeated problems.