Re: your inquiry about recurring payments, that matter is covered briefly here:
To expand on that, the main challenge with supporting such a feature is that presumably the buyer doesn't want to keep receiving the same download they got with their first payment, nor would any sellers want to provide that, and at present that's all we could actually do with notifications of each recurring payment.
Even if we added support for sending orders to checkout that would initiate a recurring payment plan, we have nothing built into our fulfillment system that could provide buyers and sellers with anything of value for those periodic payments -- e.g., tracking membership/subscriber status, administering access to a members-only system, scheduling periodic mailings/downloads, etc. In order to make support for recurring payments a useful feature, we'd need to develop all of those fulfillment features from scratch, without which support for recurring payments alone is only half a solution that's no solution at all.
While we do use PayPal Recurring Payments to manage subscriptions for the use of our own services, that isn't integrated with our cart or order-processing system at all. We just provide Subscribe buttons that help our sellers set up a payment schedule in their own PayPal account, telling PayPal to send us the same amount every month, so we just passively receive those payments to mark the seller's account as active for another month.