FPS Island Environment

Below you will find some screenshots of the game environment that I've been working on for the last two weeks.
I've been trying to figure-out how to paint multiple textures (using the texture splatting technique) with more than one stencil map.

I've used Blender 3D's Node Editor to create a network, which allows me to use as many textures as I want. The only problem with this solution is that it becomes very difficult to select the stencil map that you want to work with in Texture Paint Mode.

I don't know whether it is a bug in Blender, but when you select the stencil map in the node editor - indicating that you want to paint on to it, this doesn't update in the Texture Paint Mode and you end up painting onto the wrong stencil map.

Also, I've just finished modelling a weapon for the game. Over the next week I will be texturing it.