What Roy said... exactly!Answers are for bench and prone and for three rifles 222 REM, 270AM-braked 338 RUM-braked
#1 Do you control the rifle with both left and right hands?
Only one hand with the trigger finger touches the rifle. Other hand is on the beanie bag.
#2 Do you vary the hold according to the caliber and weight of the rifle?
No. A slight/delicate straight pull back with the trigger hand.
#3 Do you vary the hold depending on the field shooting position?
For long range hunting the position is always prone unless something miserable happens.
#4 Do you prefer vertical pistol grips vs curved grip design?
Vertical pistol grip much much more preferred!!!