Eagle1, re your first question to do with the turn, you said you understand the lift vector must be doubled in magnitude in a 60 degree bank to support the weight of the a/c. As the lift is increased so is induced drag, which increases rather sharply as more and more bank goes on. As induced, and so total, drag increases, then we either a) open up the throttle to compensate, or in your case, b) point a little more weight down the flight path to balance the increased drag. The option of thrust in a powered a/c allows us to stay level if we want, in a glider the only way to point more weight along the flight path is to point it down slightly, and voila, increased sink!!