Use the city manager tape:
1.) Go to tools (4th option down on the first page).
2.) On the next page, Cheats (the last option.)
3.) Third page:
Quest skipping - you can skip to certain quests, or you can complete the one you are currently on.
Unlock story items - unlocks from the main quest will be triggered, but further plot progression is still needed I think (for more high tier buildings).
Unlock plot type - will unlock all plots and sizes
Unlock all building classes - will unlock all building types like commerical, martial etc
Unlock all building plans - any plans that are usually locked behind quests will be available immediately.
Unlock all tools - same as above but for tools, quest rewards etc.
Hope this helps!