Now that my first sale has come through (woohoo! best $11 i've ever made

) it's got me thinking more about the client side of the site.
I know people have listed a bunch of paypal and user registration bugs which is good, I'm glad those are getting looked at. That's crucial. But I think we also need to get a slightly more functional client account section happening to keep our buyers happy and supplied with all the data they need.
For instance, the client should be able to see how much they spent on each image, as well as the date they bought it in their Account section that lists their downloaded files, as well as a link next to the image that goes straight to the EULA.
Also, would be brilliant if authors had an option to send a "Thank You - Here's a discount" email after a purchase. eg: The site automatically sent an email 48 hours after the sale to say "thanks so much for buying from me, here's a 50% discount on your next purchase" to encourage them to come back and buy another image. The shopping cart would need a little "coupon code" box where the buyer enters their valid one-time-use code to get the discount. This would reward buyers for supporting a new website and keep them coming back. Every 5 purchases, get a 20% discount code or something.
Any more ideas for improving the client-side experience? And Leo - do you think these can be implemented as part of the theme, or would they be part of your paid plugins/support thing now?