Point 1 - you’re eyes are deceiving you, now I only fly one particular brand of the Boeing family, but I can guarantee you we fly the approach with a nose up attitude primarily. It depends on the flap setting we have chosen, if we land with full flap then we are almost dead level on the approach. Basically it’s all to do with aerodynamics, wing design and high lift devices.
Point 2 - thrust is used in the approach to adjust speed, not rate of descent, we change the pitch attitude to do that, then adjust the thrust accordingly to keep a constant speed.
Point 3 - no idea.