Hi! We just stayed using the Recipe Club rate last week. We did not use room service. The only restriction mentioned was it could not be used at Shula's. We used it at Tubbi's and Gulliver's. At the same time, I used the Disney Club Card and saved 20% off the meal.
The credit does not show on your card until checking out. Remember, you can also request late checkout - I believe it was 4:00. I called down the first time and requested late checkout they said no. Then I called back down saying I had the Recipe Club rate and they said no problem we could stay until 4:00.
Enjoy your stay!