Hi, it (sort of!) already does support arbitrary schemas, or were you meaning that you want to be able to give it a schema through the interface (URL/file upload)? It doesn't currently support the later, although there's no reason why it couldn't.
Currently if you wish to add a schema just needs a thin wrapper where you tell it the elements that are to be displayed as inline (rather than block).
tldr; I'm going to allow double <enter>, and I'm going to add a [+] to the top-left of every block but that's not done yet and in the meantime you'll have to edit the XML ('view source') to make those kind of changes.
Long answer: Currently hitting <enter> clones the current block element but when there are block elements within block elements (such as chapter > para) there's no way to know what <enter> should mean. Other software (some wordprocessors) use double <enter> to step up a level, and I guess I'll support that. For UI reasons though I think that I'll also add a [+] button to the top-left of block elements (above the vertical label, above the nodeName). And I should also support pasting XML more (it kind of works right now but it needs more work).
I'll be a bit busy for the next week on a live split-view of the XML, but after that I'll work on cloning nesting block elements. I'll say when it's done on @hollowaynz -- cheers :)
