I have an idea to write an editor plugin that will, when opening a yaml file, convert it to json (or some other less painful configuration language), then convert back on save. I don't know enough about yaml syntax to know if that's possible or if there's some quirk that makes them not completely cross compatible
You could probably do this pretty easily with a simple python script. Use the yaml parser to convert into a dictionary, use the JSON renderer to save that dictionary into a pipe file. Launch the visual editor of your choice on that file. When the editor exits, read the file as JSON, parse it back into a dictionary, and use the yaml renderer to save that dictionary back into the original file.