Yes, you tap on „Kurkarte“ and use the „share“ option in the view of the Kurkarten you have purchased. Now you can forward the IDs of the individual guest cards e.g. by e-mail to the smartphones of other people.
For the actual purchase you will need, for example, your credit card number, depending on the payment method. However, you do not enter any personal data in the app itself – you can book „anonymously“.
Yes, for example directly at the EC card terminal of a supermarket. If you select „Print“ in the app for the spa card to be printed, you will receive a code and a PIN. You enter the code into the terminal and confirm with the PIN.