The risks will always be there. Product keys get blacklisted all the time even for the original Brood War and WarCraft 3 products.
Even on those older games? Dang, Blizzard really hates trainers.
do they ban the WHOLE account? lol
Your entire battle.net account? No. They only revoke your StarCraft II license. Any other games you have (WoW, classic games, etc) will not be affected. Several users that have an active WoW account have reported that they receive suspensions instead of permabans (kind of a dirty blow to show favoritism to keep their income coming).
[Edited by moderator Neo7, 9/29/2011 9:17:12 PM]