In the end, it's the complications that add character to a games experience. I would like to think there is a use for copper/iron/silver in almost everything. Especially as you advance to crystal. Tin/Bronze not so much. Different Woods, I think translate well into more complex versions of existing furniture. But in reality I find no practical reason to over complicate that side of things. Fauna, meats for more complex foods, absolutely. Hides for more complex clothes, I feel its the same position as furniture.