I have 2 suggestions: untick the Reflection_lite_Mult box, it is unnecessary and can cause other problems in rendering.  If you are using the Alternate_Diffuse/Alternate_Specular channels, it is recommended to set the Diffuse_Value/Specular_Value channels to 0, otherwise you will be multiplying the affects of both connectors, which may cause self-glowing or washed-out textures under certain lighting conditions.

And yes, you are better off deleting the AO node and letting the lights do that part of the rendering.