Re-linking to source files is a very simple thing to do in other consumer-grade media editing software packages
Hi,
That's true, even Windows Movie Maker does it very easily

I've have the same problem and had to include the medias for it to work. But if I'm not mistaken, it had worked sometime already the way you need... I feel that the relink option is often greyed these days, but I wonder if it has not been the case everytime i tried to share a "media empty" Archive between different computers.
If your hard drive is always the same and set to the same letter on each computer, isn't it possible to use advance shared project options? (I haven't yet personnaly, but I'm surely doing it now, as i have the same needs as you).