i started work on the Zoric 8 buildings today (nothing better to do) and am just popping some ideas out for discussion/change.
main goal of the island is to make it last longer, as spider said, islands can easily be reset every month, players easily get bored, new players will easily find it hard to do stuff. am hop-eing to make zoric 8 last a bit longer by implimenting some of the stuff mit has in place on zion like the multiple employees per building for jobs and slow income rates, along with some of the stuff hedge had on reine to make it easier for young players like gov owned buildings that buy stuff at profitable rates.
money will use a 10d per sheckle scale, taxes are unknown still. buildings are unknown too, but am currently considering a 20/10/10 limit.
currently, thiers only plans to use 13 vehicles besides vehicle 1.
vehicle 2 will be a default inventory tractor, vehicles 3-5 will be cars, vehicles 6-8 will be trucks, vehicles 10-12 will be boats, vehicles 15-17 will be planes.
each type is made in its own fac, has its own matching parts fac, and its own matching showroom. the remaining unused vehicles will be givin out as prizes for contests. also planning to hide some on the island in various places on the island. planes will need the piolet skill, boats will need the sailor skill, cars and trucks (besides the default v2) will need the driver skill.
buildings will be realitivly cheap and require materials only to be made. they will each take a minimum of 3 employees. production, store, and some manafacturing buildings will have 2 copies of them in the buildings list. a normal building, and a Large version of it. the large version being a bit more then twice the price, producing twice as fast, having a bit more then twice the capacity of items, and taking upto 5 employees instead.
materials for buildings will be cheap, and will many items. money will probably be easy to make, but taxes will probably also be high taxes, high food/drink needs, and high fuel usage of many of the vehicles.
landscape will continue to be the size it has been on the past zorics, towns will be smaller, and thier will be streams that are dangerous to cars/trucks. water damage will be on and high. blowing up will send you to the center of the map and probably clear your inventory (can't exactly keep Tea thats spilled all over your dashboardfrom an accident

might stick in weapons