A:AnswerEven if you have the Korean version, you should still be able to play in English as long as your settings are set to English. If buying in an American Account is easier though, then I am sure you can still play it as long as your Eshop is linked to America rather than Korea.
A:AnswerPre order would be a good idea. More and more kids are getting into gaming thanks to the pandemic better to be ready they to try and hunt it down for Christmas
A:AnswerNo but you can definitely pick it up on release day if you chose ship to store instead. Just note that it doesn't mention "guaranteed delivery" if you notice so it doesn't fall on them if you decided to take them to court for misleading. But its their way for you to go shop their store to have foot traffic.
A:Answeryea, it's call the digital copy through Nintendo when you preorder it there. Don't think no retailer will promote a midnight release except the one that opens 24 hour. Look into Wal-Mart maybe?