Lighting a room - mobile - VR...

I need some help with lighting. I am building a VR (Cardboard sdk) app that has to run on an iPhone 7, and so am trying to be efficient as possible - problem is I've not had to do mobile before and am no Unity pro either.

So, my basic needs are that I need to be able to turn up/down the lights as needed. So I don't believe I can use unlit shaders. I had a bunch of point lights and baked lighting. But still I had around 1500 SetPass calls. If I remove all the lights then I get under 100 calls...

Can I use unlit textures and still effectively "turn down the lights"? I have looked all over the place for info on how to use the "Mobile Unlit - supports lightmap" shader... Where does the lightmap for it come from?

Is there a good way to light a large room without using a lot of lights and still have them dynamic? I found I had to use a bunch of weakish point lights in order to not get hot spots on the walls - even with specular highlights turned off in their materials.

Anyway, thanks for any pointers.