About performance.
The shader actually takes the 10 textures (5 tx and 5 nm) and renders them twice blended using two different UV modes to make the terrain look good from some distance and upclose. One stretched to the master UV repetitions and one to the individual UV repeatitions per texture and normal map.
However from what I could test, removing the normalmapping on the stretched Uv repetitions improved fps from 48 to 60 on one of my tests, with almost no visible detail loss. the stretched UV mapped normalmap layers was only 1/4 amplitude of the regular ones so it wasn't very visible anyway.
This will remove about 5 of the 10 normalmap light calclulations needed with "almost" no quality loss, wghich will work better on lower systems.
I can compile a test version later this evening (I'm on GMT+1) time here.