Terrain improvement incoming + help request!

I asked my mate Warriorwithin88 and you guys what i should work on, and the answer was "terrain zomg its so ugly hurts mah eyez *_*".

Then, ill work on the terrain mainly, for .52 .
However i'd like a little help from you guys. You would get specially credited ingame and on the forum ofc.

-> I'd like someone to tell me how i can make a tile type buildable when its not supposed to be. A consistent way.
-Im ok for importing stuff, moving the whole map xcept the terrain onto a map you would have created, and such extreme things.
-I'd like an answer as soon as possible
-The main point is to have a buildable tile like the purple marble around the Well. It's to make the towns terrain.

So who's gonna help me ?