I really like that you properly captured the TAB button as indentation and not taking me to the next focusable thingy on the screen! That gets me every time on a lot of systems, so it's the first thing I tried.
I was unclear. You're saying that editor content can be exported in various formats. But I'm wondering if the editor has an explicit schema that it uses to guide & restrict the editing process, so that I can have the editor generate only a customised/restricted version of HTML, or even a different markup language schema entirely (such as Docbook).
As currently deployed, it sure is logging a lot to the console.