The Coriolis effect is when the rotor blades speed up or slow down as the center of gravity moves closer or further away from the axis of rotation.
Lead-lag or leading and lagging is the horizontal movement of the rotor blades forwards and backwards along a vertical hinge.
Lower the collective to reduce drag and increase throttle for more power, if available. If in forward flight, gently apply aft cyclic.
The three primary forces that affect wind are pressure gradient force, Coriolis force, and friction.