So I've not played gen 6 for a while, apart from going on the games to get the event pokemon. I've found out that you can get banned for modifying your save data, as they can see this through game sync. So things like max pokemiles and battle points can get you banned.
But can they ban you for having max rare candies and editing the nature and ivs of legendaries because that's pretty much the only hacking I do. When I go on pokemon global link it only shows pokemiles so I don't get how they could now if you have max rare candies or other items.