2FA is always a good option for an extra layer of security (for your account only). But I doubt that anything could happen though just by hacking your game. If anything, it can only effect your system (depending on how big the hack is). All I can really say is: Know what you're doing, don't do any game/console breaking hacks, don't install custom firmware, and keep it simple/legit. And about altered pokemon, they can't become viruses, and they can't go into HOME. Stuff like hacked eggs, items and moves that just have "???" for a name, and pokemon with incomplete code can corrupt your save data (just for your pokemon game). Then you'll have to restart. But that's it.