No, for most restaurants you don't have to pay upfront when you make a reservation.
Some restaurants only accept reservations with a small down payment, this is clearly indicated when making a reservation.

We would love to help you with your reservation. You can contact us by phone +31 10 211 00 90 or by email via [email protected]

Yes, you can use the same voucher code for a new reservation. This code is active again after you canceled your reservation. Any problems with your code? Please contact [email protected].

Once you have made your reservation, you will automatically receive an e-mail with an invitation to share your gastronomic experience with the restaurant in a review. Click on 'leave a review' in the e-mail and here you can write a review about the restaurant you have visited.