John, I put in a double crossover on my payout. (oops, typo. I meant "layout")
I used 4 turnouts and a crossover. (peco electrofrog) and Peco turnout motors.
All you need to do is insulate correctly. It may be a bit difficult to describe, but put siumply, just insulate all the turnout rails at one end. (ie, say, the two "left hand end" turnouts.) where they join with the crossover AND the straight thru track. This will prevent shorts. Then just let the feed in tracks do the powering from each end of the entire setup. However, if your inside track is running left to right (powered) and the outside track is running right to left, you'll get a polarity problem as you run "across" the double crossover of course, as your loco will try to "reverse" to match the direction of the other track, as it crosses the insulated joiners. (or make sure you have the appropriate "block" switched through to the appropriate controller.
As for the turnout motors, you might as well have all four connected to the one throw switch. The "switched mode" is only really, useful in "two modes". Crossover, or straight through for <I>both</I> tracks. That way, you will prevent accidental derailments, if you forget to reset the "mode" correctly using indvidual throw switches. ie. top left turnout and bottom right only (to switch from inside to outside). Train comes the other way, and BOOM through one turnout, and derails on the one you have not reset!!
I had a problem here, as my power source for the turnout motors was not powerful enough to throw all four switches through the one switch/circuit at once. I ended up with two switch/circuits. One for each end of the double crossover.
Hope this helps. Let me know if I've got you a bit confuddled.
