Sorry for my English, I use Translator
01 Combine textures land of mountains (Terrain-Mesh Blending), as in RAGE:
http://www.polycount.com/forum/showthread.php?t=90081
02 Importer for Custom Vertex Normals from Blender
Blender Patch:
https://projects.blender.org/tracker/?func=detail&atid=127&aid=34762&group_id=9
Tutorial (Polish language):
http://wypierpapier.blogspot.com/2010/02/vertex-normal-tutorial.html
Standard Vertex Normals (grass):
Custom Vertex Normals (grass):