You've got the basic idea. The beauty of a data separation model is that updates to the interface tend to be much more common than updates to the data file.
To rename files is not a built in Filemaker function but you can use batch files in windows or Applescripts on Macs to do this. You can also use Insert File to insert a file into a container field and then use Export Field Contents to create a new cop of the file with a new file name. You can also use Save a Copy as to save a copy of your current file, but with a new file name.