In response to the section on associative design:
It seems to me like everything started off as associative design. The first chair was a tree turned sideways and then we turned the on end and made a stump and then eventually threw some limbs on as legs and slowly the building and warping what we associate with chairs and trees.
Association is also a perspective thing. An adult might associate a box with shipping goods while a child might associate it with a cart via which they can slide down the steps and risk breaking their neck. Associative design can be an interesting way to bridge perspectives. Paint a bunch of rollercoaster carts to look like fedex boxes and we have fun way of putting adults back in the world of children.