About image links being confusing for users... Most of the vectorial illustration programas I know use links. Designers at least are pretty used to the images being linked. Anyway, those other programas also include an option on import to link or embed images, so I agree about adding that feature. Where I do not agree is about making embed default. Embedding is handy in a lot of cases and would help newbies, but a serious artists or designers would want to have those images linked, because usually they have to be edited. Keep in mind that a couple of images embedded won't be a problem, but dozens in high resolution can take the svg size too high. There's also a problem: As far as I know, it's impossible atm to convert an embedded image to a linked image without saving it. So if you imported it and it was embedded, when you extract it you'll have two files in your disk. Of course we can (and should) modify the specification to allow re-linking to an existing file as an option along with extract the embedded image. But I think that we should avoid making embedded images default until we can provide that option. And even in that case, I think we should place a preference for changing that default.
Gez