Yes, it works as you described. After the buyer finishes checkout and PayPal confirms the buyer's payment was good and completed, we grant the buyer access to a thank-you page where we present their unique download link(s) automatically, and we also issue them a thank-you email with a link to reach the thank-you/download page in case they did not proceed to the download page after checkout.
Responding to your questions in order:
1) Each buyer gets a unique download link that expires after the number of attempts or hours (whichever comes first) that you specify in each product's settings.
2) I'm not sure what you mean about an "e-junkie ebook store", but all of our features are standard and included in your flat monthly subscription fee. The only extra-fee service we offer is sending Newsletters/Updates by email to previous buyers.
3) We only send the buyer a thank-you email with a link to reach their download page. This is separate and unrelated to anything PayPal or eBay might send the buyer (such as a payment-receipt email from PayPal or an auction-won email from eBay).