First question - what kind of stuff you're planning to sell on your store? If it's some electronics, how about warranty? Most of gadgets usually have 2 years warranty. If during warranty period device will stop working properly, how about return of it to get fixed if order data isn't saved?
Offcourse, it's not an issue if you're selling some digital stuff or something what don't have warranty.
I haven't yet decided which product to sell, I have several possibilities. Despite this, this aspect is assured.
All products will be sent accompanied by the support code. For the seller, this code simply says that product X was purchased on date Y, enough to provide the respective guarantee. If the customer encounters a problem with the product, they just need to go to the website and via chat/email indicate the support code and report their problem. From then on, all the respective measurements will be taken, with the customer logically being willing to return the product, if applicable, and provide any further information that is useful for the process.
The idea is, if you never need to activate the warranty, the seller will never know who receives product X on date Y.
Warranty: warranty papers usually need a valid proper invoice, at the very least. That contains name, address...
The invoice only needs to have this data from the seller and not the buyer.
Errors do happen: what if the unique code will stop working for some reason?
In turn, the code only stops working if the seller loses the database. It can happen, but there must always be backups, whether in this type of store or in any store.
Malicious use: what if others understand how the unique code is built and start sending back for refunds goods they didn't purchase? (You cannot rely on using the same bitcoin address either, too many may be using online wallets or exchanges).
Logically, there is always this danger. Therefore, the system must seek to be robust. Either way, the customer must always have the invoice they received. The exclusive support code is only used to let the seller know that it refers to product X sold on date Y.
In other words, it is not enough to say that the code is 123456, this code must be referenced in the seller's database. If necessary, the customer must be able to present the invoice they received.
In the case of the BTC address, a lot can be worked on this subject, to guarantee the best privacy and security practices. The aim is that at the end of the day, the seller will not be able to say that sale X was paid for by address Y.
Selling abroad: you may need the customer details at least until the moment he receives the goods, you may need them in case of issues with the postal services.
Exactly. The data must be deleted from the system, days after the merchandise is confirmed as delivery. Either by the customer or by the carrier.