1) The Parcels of Land that a player can build on are fixed North to south.
2) Buildings can be placed pretty close together but not so they are touching.
3) In the Prototype you can build as many buildings on the Parcels as you want. We have had people create entire villages before. In the actual Game we will have to test it out and see what we can allow with out having the Client slow to a crawl. The Modular Building Assets were Custom designed to use as little Draw Calls and resources as possible so combined with our custom Area of Interest System which allows objects to be created and destroyed as the player moves with in range and out of range we should be able to allow the players pretty much complete freedom to build whatever they want on their parcels.
4) This is still a work in progress. Most likely we will flatten the hill to the height of the lowest point.
5) Because Players can only build on their Parcels of Land and we place where the parcels are located we will be able to control and ensure that no one builds around a Dungeon.
6) For Basements we are currently being held back by Unity's Terrain Engine which doesn't have the ability to cut holes in the terrain. We have talked about switching to a Custom Voxel based Terrain Engine post launch at which time we would be able to introduce Basements.
7) We currently support 2 floors. This will most likely be increased some what post launch as we introduce new Building Modules.
8) Each module will take different amounts of Resources. So you will need to collect wood, stone, iron, sand, ect. and then craft the Iron into nails which will be needed for the modules, Craft Sand into Glass, ect.