1.-Do you know of other extreme sports? Describe them.
Well, there are differents. Morocycling for example, or car races, as Dakar or similar, are dangerous.
Also cycling in the road, I consider it a little dangerous, sometimes bikers on road, get eighty km/hours.
2-3.- Do you know of other extreme sports? Describe them. If you have, describe your experience.
I made canyoning once and for the first time in Huesca province. I felt a little scared at first because I had to enter in a small and black hole, but it wasn't dangerous. We did it with an instructor who knew all the route and rocks very well.
Canyoning consists in walking, swimming, and jumping, in a river or the path of a river, that is full of rocks, and obstacles to over pass.