No, 1/2 throttle is not 1/2 power. For instance, I have a plane the hovers about 1/3 throttle(ends up being about 11 pounds of thrust for hovering and full power is 15 pounds of thrust) but my thrust to weight is only 15/11 or 1.36. On a good day for power pull out is O.K. by my standards(but some guys at the club think it is a rocket)--It could use more go go.

Do a search on wing loading and Reynolds numbers -- some good reading.