Hi Markus, I have split Tonerider Alnico IV's in my EX-1 and being HB's there is no hum or unwanted noise when they are reduced down to the one coil. The split SC sound is not as sharp or bright as a Strat or Tele and in your option 2 above that way they should combine reasonably well to provide similar sound to middle position on a Tele. Tend to think it will be hard to pick the difference between positions 2 & 4 though, probably very subtle if any at all.
Cheers, Waz