When I moved a scribus file the program was unable to locate images, even though they were not moved. I had to create a shortcut to original location, open that then save to new destination.
Moving files to another machine is a problem for any program of this type using linking. The 'collect for output' does the job, but dumps everything in one directory which generally isn't what one would want, but I can't think of a good alternative.
Saving as .pdf works, but opening a .pdf file ignores images, presumably due to Scribus only using linked images.