Yes, you can! In Germany, iTunes gift cards are available in supermarkets like Kaufland, Aldi, Lidl and Tegut.
Yes. iTunes gift cards were replaced by Apple gift cards back in 2022. That means you can now get an Apple card and spend it on anything Apple, including iTunes (or Apple Music).
If you have an iTunes gift card lying around, you can use the credit, as the cards don’t expire. You can redeem it online and spend it on Apple subscriptions, games, books, movies or redeem the credit in the Apple Store for physical products like iPhones and MacBooks.