It would be very useful to pipe "Get file content" data through at least a limited set of text transformation and edting actions. For instance you may want to delete the first two lines, or insert a couple of lines at the beginning of files prior to converting to PDF. A simple string substitution, evaluated on each line of text. A few lines of text appended to the end of the file content.
With the addition of some kind of flexible expression language (say, Regular Expressions), it could also be made to do some fairly neat tricks like filtering out entire lines that contain certain keywords.