Get a lighting designer involved NOW. You don't need an upside down forest of fixtures, that's for sure. You can usually find LD at a local upper end lighting store. If not working there, they should at least give you some links to folks who shop there.

An "upside down forest of lights" is exactly what I'm trying to avoid! Unfortunately, I live in a very small town. We don't really have lighting designers, and I'm planning on buying my fixtures online.

Light the walls first with wall washer recessed fixtures, then light the passageways with small diameter recessed down lights, then light the task areas like counters. Use PAR 20 tungsten or warm LED lamps instead of R lamps. Use hanging lights over an island if you don't mind them blocking your view when standing but if they don't produce enough light use tiny LED pin spots between them.

The stair will not work nor will it pass inspection. It needs a lot of work to be useable and attractive since it is the central feature of the living space.

I recommend some kind of ceiling treatment to help give the different parts of the plan more identity.

Renovator8, If you are talking about the wedge steps, those will not be in the real stairs. That is just a place holder that is the closest thing the app has. My very experienced builder has the steps laid out, but I don't have a copy of his plan right now. I know that the one open space is not for everyone, but it works very well for my family. Thanks for the lighting advice, even though I'll have to Google some of it!