Uranus is much much larger than Earth, so the distance from the planet's center is much much greater
Here stress is parallel to the surface of the body. So it's a Shear stress.
Speed of any freely falling object is always same. Provided, both are left to fall from the same height. If you perform this experiment in a perfect vacuum or near vacuum laboratory, both of them will reach ground with same velocity this is because there is no resistance to their motion. This is always true no matter where you go and perform this experiment.
It can be easily proved from conservation of mechanical energy. Why conserving energy? because there are no forces acting on the freely falling objects other than conservative force(mg).
The best thing to do is start out small. Do something that is in your comfort zone and get bigger each time. Before you know it, you will have gotten over your fear and it'll feel great :)