I've written an article on the various reuse mechanisms in EPF: sett.ociweb.com/sett/settJan2012.html
Being fairly new to EPF, I found myself getting confused some on all the ways EPF can take a content element and allow it be reused in a variety of different ways. I wrote this article to help summarize and consolidate all these ways.
If you've gotten similarly confused this article may be of help to you too. If you see any errors or omissions please feel free to reply and point them out.
I want to thank you for this. I have been using EPF for 3 years and due to pure busy-ness I come back to re-use regularly and have to occasionally remind myself how it all works, especially when I need to train a new person. This is very helpful and a great guide. I'll make sure to try most of the variability you describe because 1) I need to, and 2) just so I can see how it works. Very timely, at least for me.