Does this kind of credit work on international Amazon sites such as .de or .jp?
Nope sorry .com only but .com ships to most countries so just let me know what item you need and ill see what can be done.
Is this amazon gift card balance? Is there any way that you can transfer some of the balance onto another account?
Balance is transferable only if it hasnt been used which is not the case here so i am unable to. If you are worried to disclose your address you can always make a wishlist i can buy directly through wishlist