a new user expects the document to be self-contained.
This is too vague to be valid. For example, when I started Inkscape (as a new "Inkscape user"), I was glad to see that it was links. This was because of my previous experiences.
As Jon said earlier, there is no solution that fits everyone. We just have to make it clear for everyone when it's Link and when it's embedded.
Here is what I propose :
- For import : Put a drop-down menu in the import dialog, on "Embed" by default.
- For copy/paste : embed, the user will the use the "Image properties" if he wants to create a Link - For Drag and drop : Ask every time the user if he wants to create a Link or to embed. Allow hom to tick a box that says "always use this choice" (this property can also be reach in the userpreferences)