You can be relaxed about my opinion of your post because I like a lot your idea of applying our workshops in a school and let the children participate actively in it.
I like the way of involve all the teachers to reach one objective related to literature, because it can be one part of curriculum that we forget when we work on it.

The only think I can tell you about this idea is about the time. In my opinion, one workshop every two weeks can be an stressful work for the children because when you finish one, you have to think about the next one and they have to do other things at school, not only one project, but a good idea could be make this workshops every month, so you can teach your contents or the book normally during 2 or 3 weeks and the last one be focused on the workshop.

Also, it can be related not only with a book, you can take some characteristics of it and apply it. For example, with Aladdin, you can take the topic of the desert to create a workshop about different landscapes or about the weather.

In conclusion, I like a lot your idea and it can be a good project to apply in a real school and see how children create them.