Landscape, World composition and speedtree

I have been looking for automated terrain texturing for some days. After finding a good but old tutorial I found how to use height/slope blending as well as a combination of the two. I tried it on a hand-sculpted landscape and it works like magic. But when I use it on a imported landscape(World machine), it doesn’t work ie only the height blend works but not the combination. Please tell me what is wrong with my imported heightmap?

I really liked the ice veins in landscape mountains. Could anyone tell me how to achieve that? This is an additional query.

Here are the Screenshots.
!!!alt text][1]][1]][1]height blend perfect.PNG

Here’s how the material looks on a hand-sculpted landscape.
height blend imperfect.PNG

Down below is the material when applied on a landscape created from an imported heightmap. alt text As you can see , only the height blend works or rather the slope blending is somehow overridden by the height blend. Also the height blend is absolutely disoriented. the dark yellow colour which you can see covering most of the landscape is actually meant for areas below sea level.

I have made a good 8k landscape using world machine but keeping in mind the performance cost I decided to use world composition to use tiles rather than the full landscape. Then I followed tutorial to correctly set up everything. But when I imported the tiled heightmaps under persistent level, all the sub-levels were grayed out and and couldn’t load any of them as specified in the tutorial. Have I missed something??

Moreover I am using speedtree to make my tree models.
From what I learnt I need to isolate the leaf in a white background with an alpha to indicate that its fully transparent. How do I go about doing this?