Many thanks for the beers!
That is good feedback, I did not know about that requirement for Authorize.NET, could you post a link to that information so I can find the details of the requirement? I think I will nee to implement a new page in WebStore for refund policy. I will put that on my near term to do list.
As far as extending the WebStore, it is too early in the development of the feature, I have not yet even begun to think about an extensibility strategy for developers so I really have no advice at this point. I need to complete all the basic functionality first. The current code is completely subject to change, so its still too much of a moving target for me to think about how to make it extensible by developers. The only immediate strategy is to clone it and fork it with customizations, but obviously thats not a great strategy since you won't get ongoing imporovements that way.