a) More than enough space for 6 major settlements. Hey, i sometimes mod (more like twick the games a bit), though hardly an expert, i've been playing ck2 and ck2 a game of thrones for a while, and i sort of get stuck with picking the same capital whenever i'm a dragon rider, because i always make a point of getting Dragonstone thanks to Dragonmount the unique building that makes dragons grow faster and increases their life span, i like.
There are stone pits and mines in mountains, vineyards in hilly terrain and lumberjacks in forests This modification adds over 40 new buildings and its extensions to the game.There are numerous new ones, but the most exciting are terrain specific buildings like corn farmes that boost your income and do other useful things. For this example I am going to add a simple statue to my castle that will provide some.
Once you have located the buildings folder you will need to add an entry to the one of these files that corresponds with the type of building you wish to add. Usually it is something like: C:\Program Files\Steam\SteamApps\common\buildings. Yes, i know, but i already have some ideas for wonders which doesn't really work very well for the current building system, the modifiers you can use a fairly limited, there should be more interesting options the First locate the buildings folder inside the CK2 file structure.