Do brakes provide full power when used from the hoods?
most mid level and up brakes / levers will offer 75% or better power from the hoods. Max brake power from the drops. 

The handle bar position is critical on long rides to offer 3 or so different hand positions. Start with the hoods level, to just above level and move around from there. I tend to micro adjust them as i get comfortable on a new bike. Seat height, frame size, stem length all play a factor in finding that sweat spot.