Out of the 8 or 9 eflyers I've seen, no one has a switch to turn things on or off. I've always considered it extra weight and something else to possibly go wrong. Plugging in the battery is what turns the plane on and off.
On all futaba compatible servos I've seen to date (Waypoint, Blue Bird, Hitec, Futaba), the negative wire is black, this is the (-). The signal wire has been a variety of colors, white, usually, but orange or yellow too. Positive (+) wire is in the middle. So as long as you line up the black wires, you should be fine.
The fuse goes between the SC and the motor, I don't think it matters which wire. It doesn't seem like too many people actually use them though.