I would suggest that the note-icons in the create-note-toolbar are a little bigger and followed by the corresponding shortcut directly visible. "note" (6). The should be plenty of room for it in the toolbar.
Also a better indication of when you are in edit mode (and maybe play mode ?) in supplement of the little box down in right corner. Maybe some symbol a couple of places on the screen, or some kind of "watermark" ...or..... or...