Ambient occlusion is definitely a great thing, it adds more depth to your scene and makes the whole thing look more realistic.
Just one note: when setting the global light intensity to 0, make sure you have at least one light in your scene. If there's no light, Anim8or uses a default light which is not affected by the global intensity settings...
As for Phong shading, as far as I know it's not anything "special".
In fact Phong shading is one of the most commonly used shading algorithms and it's the default shading method used in Anim8or - the Phong shading method is always used unless you add attributes to your materials and use the ART renderer.