So driving in the snow isn't that difficult if you have the right cars. A car with four wheel drive is very helpful. Chains on the tires works as well, but I've never needed them. You need to be careful going around turns ad its pretty easy to skid. Important bit about skidding is to turn in the direction of the skid, but if you are sliding down the hill I guess it doesn't work that well. SLamming on the breaks is actually really bad as it stops the wheels from turning and provides no traction at all. You wanna very gently use the breaks at increasing pressure and alternate stepping on and off the breaks if they aren't ABS. Generally people try and come to a close stop so they go down the hill pretty slowly, hills suck. Your friend did the right thing though, snowdrifts are generally pretty good, so Yay, you survived.

And wow that was a long rant on how to drive in snow and ice. If I have time I'll respond to all of the other lovely things you mentioned.