1) The black wire of the SD pup would be the red wire of a DiMarzio. This is the 'hot' lead.

2) The green wires are the same. The 'return' lead.

3) The balck and the white wires of the DiMarzio pup would be tied together to give a normal humbucker configuration. This connects the coils in series.

4) Using the pot shell as a ground point is sloppy workmanship, in my opinion. You not only risk damaging the pot with excess heat, but if the control cavity is foil lined, you will be creating 'ground loops' by giving the return currents more than one possible path. All of the ground connections should be run as separate wires that connect only to the shell of the jack.

5) For some more switching options, go to

http://www.dimarzio.com/site/#/pickups/

and select "High Power", then "Tone Zone". Clicking the "Installation" button will bring up a PDF file explaining how the pickups are wired, and what options are available for selecting different sounds.