Gene,
1. See Chuck's answer.
2. See Chuck's answer.
3. Real 1:1 turnouts move slowly and do not snap like the Atlas etc. turnouts. That is the only reason I can think of for using slow-motion switch machines.
Tony's Train Exchange makes a neat little package for the Circutron switch machine, the Tortise and the Hare. These electronic attachments consist of a stationary decoder and signal system all which just plug onto the switch machine. Each stationary decoder is programmed with its own address and you select it just like you select the mobile decoders in your locos, telling the machine to throw the switch. The Atlas unit that Chuck mentioned is capable of controlling multiple turnouts with multiple addresses. You will note in the picture the three wire hook-up locations. This is where you connect the wires from the Atlas switch machines. The other two wire connections are for power to the stationary decoder. I'm not familiar what the power requirements are for the Atlas stationary decoder but I assume it could come from your old unused DC power pack. You know, the one you will use to control the lights in your structures......unless you use stationary decoders to adjust the intensity of the lighting for day or night running and special effects.
The possibilities with DCC are almost endless.
Don't forget that you will also need a bus for the handheld throttle if you want to walk around the layout and plug into it at different locations. I have 4 dual stations on my layout. Actually I need to buy another throttle for guest use. Right now I control everything from the one Power Pro hand unit.
Meanwhile, back to the turnouts. I like to follow my train around and use hand throws only, no powered ones. If you have a switch in a location you can not reach or you prefer to run the layout from one fixed position, your powered turnouts are necessary. The good news is that you have not wasted any money, but you do need to spend some more if you want DCC controlled switch motors. For now, just leave the turnouts powered by the DC transformer and save your pennies. You can always hint at what you want for Christmas......slo-motion switch machines and stationary decoders....HEE, HEE!!!!
B-)