I think you've addressed something pretty important. There is a difference between where something is stored and what is being stored. My issue with the folder

I think you've addressed something pretty important. There is a difference between where something is stored and what is being stored. My issue with the folder metaphor is that it assumes those two are related when it reality they can be completely decoupled. Choose to save the file either on HD, external drive, or online, then choose how to find it, tags.