There is a decided lack of information given about the snowball skills.
The list of what I’m aware of is as such:
Ice Wall causes a blowout to those near the center when cast.
Quick Shot does terrible damage from the front, decent from the side, and high from behind.
Evasive Shot causes Cripple on hit.
I believe Rapid Fire does more from behind as well.
Snowblind gives you Swiftness on use, and stealths in an area around you.
Obviously most of these are in Scout, and are the reason I thought it was completely awful at first, because I did not have this information. With this info, however, it becomes painfully obvious that flanking is essential to do anything (aside from your squishiness if you try from the front).