Before I close this up, is this legit location for light at bottom of stairs? Yes, switch at top and bottom, and light at top as well. Through some quirk of symmetry, this can light (of 12 total), ended up HERE, and lines up with the other cans in a row (not pictured. And yes, that is an emergency light, not required per local code but I be losing power in ice storms. I see a lot about how many candle feet, etc…the stairway has to be illuminated, but nothing about how many inches/feet the light source has to be positioned in relation to the top and bottom. The top one is almost directly over the top step. Bottom one, it does the job. I'd hate to add another can there, it will look odd, but I got final coming up soon else have to pull a new permit under 2017, and I'll take an odd-placed can versus re-permitting as a new build.
Best Answer
The only thing that worries me is odd placements of the lights and switches requires more wires than a typical /3 cable includes, and that invites bad wiring, e.g. using two 12/2 cables where you need a 12/4 cable.
Also, in this day and age, remember the light switches need real neutral at the switch. 2-wire switch loops (3-wire if 3-way) are outlawed in 2011 NEC.