I think its better to give a link to the app. Buyers can download it and you are not bound by the GPL license for your app either.
Lester is right, there’s a help file in the package you downloaded when buying the template. It should explain pretty much all of what you need to know to customize the template. If you are afraid of the word “XML”, here’s a helpful tutorial diving right into it http://blog.activeden.net/resources/common-questions-by-flashden-buyers/common-questions-xml-explained/
I think those should be sticky or have a button of their own, so the buyers have an easy access to them.
Thanks for sharing! Nice icons!
Congrats, guys! Looking forward to see what files you come up with