Starting with first things: are the book submissions closed when the book goes live?
As for the exhibition, we should try to take this to disavantaged communities, schools, etc., we did something similar in Mozambique for the first photography festival, PHOTOFESTA, we projected photos in several informal settlements, cultural associations, bars and outdoor spaces in and around Maputo. Even when there wasn't electricity available near by, the will of the spectactors was so strong that they would always come up with a solution (sometimes giving new meanings to the concept of "extension chord").
I also think we shoud avoid galleries or spaces where art is treated mainly as an economic commodity from their 70% commission, there's a lot of public spaces that might be available to exhibit as long as we follow the right channels.
Sometimes a wall is not enough, depending on texture, color, smoothness, etc. we should also try to get a projection screen, when and if possible.
Your excitement is contagious.
I'll try to drop some more thoughts as the idea matures.