I have created a site proposal on Area51 for questions regarding plot, story, and character development. Such a site would be a valuable complement to both Worldbuilding and Writers.
Please participate in that proposal, if you are interested in asking or answering questions on:
- character development: personality, backstory, relationships between characters, character arc, goals, flaws
- plot development: filling in plot holes, organising parallel storylines, finding a fitting resolution, increasing suspense through turns of events, deriving a plot from a setting, character, or other idea
- story development
While all these topics are on topic on Writers, Writers takes a more theoretical approach to them, requiring questions and providing answers that are useful to all writers. Examples on Writers are only meant to illustrate the question.
This site, on the other hand, is a brainstorming and idea generation site for individual writing problems. What Worldbuilding does for worldbuilding, this site does for plot, story, and characters.