Not sure yet, working on more basic features now.

I did try AEC and even got it to work. Then I needed to fix something else which required removing things including AEC and when I tried again, I couldn't get it to work! My concern is that even if I got it to work again, I still couldn't be sure how to fix it if it went wrong. The hacks are a little confusing and also a couple say that I need access to my server. The server folk at Siteground say it's all working anyway so they do not need to fix the hacks. In short, a bit out of my ability range to be confident about. Will be looking at JContentSubscription (advertised on iJoomla) and still waiting to see what the pay add-on from the CB team might bring.

You must have mastered AEC! Well done.

Thanks for the feedback. Paypal flow is definitely on our list, but remember guys, programming TAKES TIME. 

No at this point.

Almost everybody has a different idea of what is the most important feature digistore is missing. We listen to all your suggestions and we make our priorities based on your feedback plus what we think is right.