In Germany, you can use PayPal to pay directly at Apple.com. This means that you can also choose to buy Apple Gift Cards at Apple and pay for those with PayPal. You can use the credit on this card for your iTunes subscription.
With this digital gift card you can buy anything Apple. You can use it to spend in the iTunes Store, or on Apple TV or Apple Music. You can also use Apple Gift Cards to buy Apple hardware both online and in the physical Apple Store. You can buy, for example, an Apple Watch.
Some webshops give out discounts on Apple Gift Cards from time to time. You’re most likely to run into deals during holidays like Christmas, Black Friday or Cyber Monday.
Yes, you can! PayPal is available as a payment option in the Apple Store.
You can't transfer iTunes credit to PayPal. Once you've added iTunes credit to your account, you can use it to buy anything from the App Store.