Most people leave the gyro adjustment wire unplugged because the stock Esky transmitter has very conservative and non-adjustable settings for rate mode and heading hold. Have a look at your tail servo with the heli powered on. Is it slowly drifting in one direction? If so, you can try using your transmitter rudder trim to find a setting at which it doesn't drift. Normally this would be done using subtrims, but the stock transmitter doesn't have that option. As for the rotors not turning until you reach 1/2 throttle, check to see if you have enabled soft start in the ESC program (you want it to be enabled). I suspect that may be a possible cause to the delay in power up of the motor. HTH