I spent another 15 minutes with the structure editor, and I think I understand the content model now. During my first encounter it was very difficult for me to discover why when I edited an article, I only saw metadata + lead-in, but not content. I now understand that the content is a series of content blocks that I can edit and rearrange in the structure editor.
Looking at the "A Shifting Reef" demo article, it's still somewhat surprising to me that a document containing a lead-in, a paragraph, a blockquote, three more paragraphs, and an image can't be edited as a whole document. Instead, it appears to be treated as an array of [pagemeta], [text], [blockquote], [text], and [image], all of which must be edited separately.
My understanding is that if I wanted to move the image up two paragraphs, I'd have to:
1. Open the Structure Editor
2. Create a new, empty text block below the image. Save it.
3. Open the text block before the image, cut the last two paragraphs. Save it.
4. Open the bottom text block, paste the two paragraphs. Save it.
If I lose my clipboard between steps 3 and 4, I lose content. Similarly, if someone visits my site between steps 3 and 4, they see broken content. Django CMS has a strong enough reputation that I'm completely willing to believe that I'm being dense and missing something fundamental here. I'd really appreciate your insight as to what I'm doing wrong, and what the expected workflow is. Because right now, that all seems unreasonably convoluted and unsafe for rearranging an image or blockquote amongst text.
I guess this would be less of a problem if I could somehow see a stack of all the structured content editors for a given articles, and change them all at once before saving, but I can't seem to find anything like that, either.