I would say -3c to -5c is the best temperature for skiing.
Yes, they are. That's why it's called Alpine skiing!
55o F is ideal.
Not sure on exact temp...but it needs to be COLD.
Yes, they would have skiing in the (biome) tundra. By the definition the tundra is an area with low tree growth and short growing seasons(because of the cold). Because of this the tundra is actually ideal for skiing in.
The ideal water temp. should be around 80°F.
700000 degrees farinheight