Global illumination? I think that's just for yafray. I've toyed with it before, but I don't use yafray, because it isn't compatible enough with blender, for instance, some textures don't get rendered, it can't render halos, and more. Also, id doesn't show you the progress it has made; it stays black until it's completely done, which takes a while just with the blender internal renderer. The random rocks part was kinda easy; there is a feature which allows you to align them to the terrain and snap their local coordinates to match that of the terrain. I just have to hold ctrl after pressing alt-d every time I want a new one. I tried doing it with particle systems, but they intersected, and there seems to be no way for random particle rotation to rotate around the local axis based on the initial rotation of each particle.