I’m not too familiar with ditto, but as far as managing multiple sections in one page at least one way would be with Template Variables. However, if each section needs a WYSIWYG editor you could create a document with children and then have each child correspond to a section on a page (This would enable you to use the WYSYWIG from each document since TV’s don’t have a WYSIWYG editor).
So, if the parent document is "My MultiSection Page" you might have three children placed under this resource "Section 1", "Section 2", etc. In the template for this page in the editable area for section 1 you would write a snippet that gets the content from the resource with the id that you want. Or, if you wanted to have the documents populate underneath each other, you could just write a snippet that grabs all the children and inserts their content successively on the page.
Here’s an example of just that on a modx site that I created.
http://www.reasonablefaithdallas.com/index.php?id=2. Whenever the client wants to create a new event they simply create a new document under the "event" folder and all the event documents are then sorted by date and populated. Now, for this particular page I used Template variables rather than the WYSIWYG editor, but the principal would be the same.