Does the inertia force change the angular velocity due to increase-decrease in the radius when the blade travels up? Does this cause an excessive bending moment?
A helicopter rotor usually has flapping hinges, which lifts the blade up when travelling forward and down when travelling backwards. The blade being at an angle indeed causes a change in effective moment of inertia: it would want to speed up when at an incline, and this would indeed cause a bending or warping moment were it not for..
..the Drag Hinge or lead/lag hinge. The image is from this site which contains an explanation on other rotor heads as well.