Uncheck the Reflection_Lite-Multi, you do not need that setting in your materials.  

I am noticing the Diffuse_Color chip is gray for the wall sample image you have included in the post.  In my workflow, I change the colored chip for Diffuse_Color to white and change the Diffuse_Value to compensate.  Try a Diffuse_Value = 0.85 first, then adjust with slightly lower values.  My reasoning for this approach is to retain some diffuse lighting reflection for the lighter textures.  Real life material do not reflect diffuse light 100%, some of that light is absorbed and scattered; darker material would give off less diffuse light than lighter material.

Skydome shaders look as it should.

The Step 1 final render looks very good.  I like the progress so far.