Brief explanation:
City is in 3 sections: Downtown/industrial, commercial and resedential.
Downtown is in the middle, and is separated from the other two by highway, lake and forest. It includes all the headquater-type builds, promoted skyscrapers/large buildings and the police and fire stations. Behind the metro area, in the mountains, is the industrial, where mining takes place. All jobs begin in this area, except for shopkeeping. The assasins HQ is the only building type allowed to sell arms in the city, but the police station supplies officers with legal weapons (ie jobtype=sales available). The section of the industrial area which borders the lake may be used for a ship-port, but with industrial theme. Boats should be available as a vehicle purchase.
The forest is the best source for trees, and all tree-cutting occurs here. Map is exaggerated heightscale. The forest also serves as a gap to prevent lag between the city and the commerical area.
The commercial area, the beach/boardwalk and all normal commerce is in one spot, at one end of the highway. All restaurants, gun shops and supply stores are here. Ideally, only 'legal' gun stores, food shops and supply stores, no one-size-fits all stores or illegal weapons. Best builds are 'promoted' to the boardwalk area. Perhaps there is a ship port (Nil's idea) under the bridge, at the furthest west point of the commercial zoned area.
Travelling down the highway, there is one major exit to the metro/downtown area, we pass that, go over the bridge and enter the resedential area. Most people build here, build sizes are limited, and 'promoted' builds get optimimal slots, the cliffs and the mountains being the best. Parks are welcome, but retail is not. Illegal weapons sales may occur here, but not very openly.