Baking Textures? What can't I do? I really hope someone can answer this because I've looked all over and cannot seem to find the answer/solution that fits my problem; or maybe I just don't understand how "baking" works.

I created a model in blender, unwrapped it, exported it as .fbx into Substance Painter and added my textures there. I then exported those textures to Blender and applied them using the node setup pictured. 

My texture is visible in render and fits the object correctly. All textures: image, normal map, reflection map, etc. work correctly and render properly.

My problem? I'm building models to export to Unity for a game and I don't want the game engine rendering everything so I want to save time by baking my textures onto the object. If I just connect a single image texture node to the material output it will render and I get a usable baked texture. But with the node setup pictured it just renders black to the image I'm baking to.(pictured)

My question: Am I trying to hard? What all do I actually need to bake onto an object to be helpful in Unity? Can I bake normals, reflection map, etc. onto a single image texture in the first place? Should they all be baked separately and attached to the object in Unity? Can my above node setup be solved in order to render everything onto a single image texture?

I know it's a lot and I have looked at "workflow" guides but I do not understand where I'm going wrong here. Any help is appreciated.
Wouldn't it be a simple light problem...

If your lights are not setup wright as you want your scene to be lit, then you have nothing to bake since the texture you already have...I guess what you want is to have the object lighten as it would be if you put some dynamic lighting in Unity...