Survey turnarounds

Please, look. Why my quadcopter flies the survey mission like this?
Distance between lines about 15-20 meters.
I need the most smooth turns, but it make only one turn about 180 deg and have a great pitch and roll oscillations on move back.

Please update to ArduCopter 4.1.3. It uses S-curves for navigation per default. And will do what you want.

But you will probably need to improve the tuning of your copter if it oscillates in pitch and roll.

Why is it missing the lead-out waypoints all together? What is the waypoint radius set to?