I'm not quite with you ... yet
If you export your project with full media you get a single file which is called xxxxxx.spryzip
That contains all media and the project
If you then delete all the original media from your iThing you can come back to the project by importing the spryzip file which will put the media in the right place for you to continue editing your project. You could also open the .spryzip on a different iThing and edit the project on there. I have started a project on my phone while on the way home on the train and continued on my iPad
The spryzip file is a zip file containing everything so if you open it as a zip file ie unzip it, you get all the files back
Am I getting it yet?
If you manually move the media to another location then the project won't know where to find it and will show 'missing media'. You could then drag the media from the new location to the timeline but it is a lot of work and would almost be as easy to start the project again