With physical goods, the seller is paid by default (when the seller responds). With intangible goods, nothing the seller says can get the chargeback reversed. You only get the money if the buyer responds, which they rarely do because they are about to get a full refund and free product. PayPal's only recommendation is to capture the address (and send a free CD). I found that just capturing the address made the problem mostly go away. And with the couple of chargebacks, when I responded with the address, I was paid.
2. Nothing prevents me from putting a fake address into the form. I just did.
3. The web page does not use SSL-encryption. It doesn't process credit card information, but it surely does process personal information such as my address, which is enough to be a violation of privacy terms in Europe.
So, while I found the copy of this web page extremely interesting and it just "worked" on me, the technical aspects were almost a deal-breaker for me and I only circumvented the problem by providing a fake address.