There are many:
Gravity pulling the skydiver to the ground as well as wind resistance pushing up on the skydiver.
Gravity pulls the skydiver towards the centre of the earth (downwards force). The air causes wind resistance, slowing the sky diver down (upwards force). The wind can also cause a slight sideways force upon the skydiver.
If you mean "balanced forces", no: if forces are balanced, there is no acceleration.
Drag, I think? drag is good
gravity
net force and gravity and possibly a parachute
when a skydiver jumps out of a plane, the dominant force is gravity, pulling him/her towards the ground, although some air resistance is also acting on him/her, allowing him/her to fall at a steady speed (not dropping like a stone), so the forces acting on the skydiver are almost balanced. of course, all that changes when the parachute opens. then the air resistance greatly increases, drastically slowing the descent down to earth.
An acceleration requires an unbalanced force.
Certainly. Say you have an object that has been falling through the air for a long time, say a skydiver. After falling for a long time, the skydiver will fall at a constant velocity. This is called terminal velocity, and this is when the air resistance pushing up around the skydiver is equal to the force of gravity pulling the skydiver down. The skydiver is not accelerating. By using F= ma, with zero acceleration, there is zero net force. The skydiver is moving as if there are no forces acting on the skydiver.
Gravity pulling the skydiver down towards the earth. And friction (air resistance) acting in the opposite direction. The force of friction increases as the the skydiver falls faster until it is equal but opposite to the force of gravity. When this happens the Skydiver has reached terminal velocity.
cartomancy
The friction is the wind resistance the skydiver experiences during the free fall. If the body is held horizontal to the ground, arms and legs held out like a cross, the wind resistance increases and the body is slightly slower than if the skydiver turns vertical to the earth, as though diving off a diving board into a swimming pool. There is a terminal velocity of approximately 60 m/s for a typical skydiver in free fall.