is there a way to avoid duplicate printing of documents- either by dynamic stamp printing as documents are printed, or by automatically moving documents from a "to print" folder to a "printed" folder?

Well, I do not quite understand your request, but if you want to avoid reprinting a document, you should not print it again. If you want to mark it “printed”, you should ask Microsoft and Apple to introduce such a flag.

You should be able to make a Custom Action to print the files in a directory(s).  It would not duplicate print anything that way.Find the Action Wizard tools and follow the prompts.

I hope this is helpful.

My best,

Dave