All three comments are actually regarding ODF 1.2 part 1:
Regarding the file extension "odi": This is an extension for an image format, which is different from the graphics format (ODG). This image format has been requested for ODF 1.0, but it may indeed not be widely used. Before deprecating it, it's actual use should be evaluated. That's something that may be considered for a post ODF 1.2 version.
Regarding <presentation:notes>:
This element defines a notes page, which is a page that contains a preview of a drawing page and some additional graphic shapes that contain author's notes for the page. The description may make that clearer. OFFICE-2589 has been created for this.
Regarding SVG fonts:
The SVG font elements do not define fonts, but only information how to choose an appropriate font. There is no alternative in ODF to provide this information (except that some requested properties of a font may be specified by formatting properties, too). For that reason, it is not required to state that the use of SVG font descriptors is recommended.