This is information I gleaned from the website you linked to, and the F3AF manual, which is posted at MIR. Take it with a grain of salt, I've never handled one of these myself.
The DX1 finder takes a pair of AAA batteries.
You've got to remove the normal focus screen from any F3 before mounting the DX1, as the DX1's screen is permanently attached.
It can only autofocus on the dedicated F3AF body, and only with the two dedicated lenses (and a teleconverter) made for that camera.
The DX1 finder should work as a viewfinder with manual focus or autofocus lenses on any F3.
Many (but not all) Nikkors of aperture f/3.5 and faster will allow the manual focus aid (AKA "electronic rangefinder") to function.
Might be more trouble than it's worth. This was Nikon's first attempt at an AF SLR, and it wasn't an enormous success.