yes, if you play a steam game and hack the game by using aimbot or something, the whole steam account will be banned. Don't be stupid for hacking/botting a game if you have a hundred games on your steam account.
steam doesn't have the right to cancel all subscribtions / revoke all keys under the account if you cheat on one game. they will revoke that key only if you break the game rules. and this question is silly. There is no vac under PoE. to be VAC banned you need VAC games.