No not yet but they might someday.
They are not
According to Roller Coaster Data Base, there are currently 174 wooden roller coasters operating around the world.
"In 1959, the Disneyland theme park introduced a new design breakthrough in roller coasters with the Matterhorn Bobsleds. This was the first roller coaster to use a tubular steel track. Unlike conventional wooden rails, tubular steel can be bent in any direction, which allows designers to incorporate loops, corkscrews, and many other maneuvers into their designs. Most modern roller coasters are made of steel, although wooden roller coasters are still being built." - Wikipedia
I believe not.
11. But, there will be one more added in the Spring of 2012 to make it a total of 12.
Some do. A wooden one usually does, but sometimes you can find some that don't. And steel roller coasters almost never do.
The Carts for the roller coaster are attached and hooked around the track so it can do anything to the extreme such as, up side down turns, corkscrews, and so forth
If you are looking for a palm sweating, fun time, the wooden roller coaster sways a lot more.
At Cypress Gardens a boy stood up on a wooden roller coaster and died
Depends on the manufacturer, speed, height and the actual ride.
All roller coasters have at least one hill and one drop. Most roller coasters also have turns as well. Inversions (going upside down) is typical on steel coasters and rare on wooden ones. Their is always some way to start a roller coaster, a chain or hydraulic launch systems are some. Brakes are on every roller coaster as well.
Wooden roller coasters give people such palm-sweating thrills because they have lots of quick swift drops and crazy turns. Of that adrenaline junkies can't get enough of. However, steel roller coasters may have the advantage of being able to be manipulated to loop and corkscrew.