No.1. I plan on going full passive with bi-amp option and the switch thing as I will be using quality grade parts for the x-overs. I don't plan on going active. Will the switch thing be needed in that case?
Those networks you are looking at are bi-amp only networks.3. Inductors. The 4344 mk2 schematic notes using iron core and air coil inductors. Giskard in his equivalent used only air coil from what I see in the pic below (left side, courtesy Giskard):
I use iron cores on the 2245H and 2122H as shown in this "in progress" photo of the final revision of the full passive 4344/4345 equivalent network with bi-amp option.
The total DCR has to match. However you accomplish that is your choice.4. L-pad inductors (on pic, courtesy Giskard). Is it possible to buy this stuff anywhere? Or will putting in a huge 3.5mH inductor and 10watt resistor be just as good or even better?