well for structure wise, i would like an FTB server where everyone works on a certain mod, like you have a city that has shops in the downtown and a group of peopl owns and runs the shop and develops through the stages of technology, as the server ages, more will come and join the server and speacialize in each modpack, then after like a month with one modpack, everyone switches to the next modpack, and in the stores they only sell like the raw materials, and you have to produce effort to make stuff and make your house awesome so you would still have to mine, the could be a quarry company that does quarrys a mineing well a pump company, you could hire people to do stuff, its just an idea but it might be fun