1) Long slender leaves ("needles") because:
a) They don't lose a lot of water from photorespiration b/c of low surface area
b) Snow doesn't pile into the branches and break the branches off (snow is very heavy). the needles don't catch and hold very much snow.
2) The wood is soft and bendable. Strong wind doesn't break it, because it flexes. Any snow that does manage to pile on is dropped when the wind blows, or when the weight of the snow bends the Branch down.
Hope this helps! :)