On the issue of linking vs embedding images: can't we just have 2 commands? - Embed an image - Link an image
Those who don't understand what Link an image means probably expect the first behaviour anyway.
I'm among those who was surprised by the behaviour. I use Inkscape as an image editor first. Even if Inkscape is used to create svg files which were initially destined for webpage content, the difference is inconsistent treatment of similar objects (from casual user POV).
For html, there are: - Images (external objects, must be attached separately) - Text (part of the html file)
For svg, for the really clueless user, there are: - Graphics - More graphics (just with fewer editing options)
This is perhaps a simplistic view, but what do most users know about the subtleties of image objects? There's a whole segment of users out there for which Inkscape is "to create images, like Photoshop, except Inkscape uses vectors, which is like manipulating lines and moving around shapes instead of adding blobs of paint."