Well that's a hell lot of calculation....but still the most appropriate answer...that yes bitcoin address have to be unique and you will won't run out of these address so easily ....hahahha
Yeah simply same like QR addresses. Each will be unique among all the wallet addresses. Some the trading site and wallets use to change addresses but the transaction has been received to primary wallet of it. Then we can get the customized wallet address by paying for it. It can be available in digital goods section not sure where with the child board or thread name. Please check.