First--I believe the section does not require lighting outlets on the stairs as it says "Where one or more lighting outlets are installed for interior stairways...", it doesn't say they must be installed.
Second--If you decide to install lighting outlet(s) for the interior stairway(s), and the interior stairway(s) are 6 or more risers, that each lighting outlet installed for lighting the stairway needs to be controllable from each floor level and landing level with an entry way. This means three way and/or four way switching is required.
I don't think the wording allows for separate switching for separate lighting outlets for the same stairway.
Third--If you install lighting for any interior stairway, the three-way/four-way switching is required. The section does not differentiate stairways to different areas of the house. Are pull down stairs a stairway-not sure.
