3. In the minigame, shake a fruit tree, pick up the fruit and after the game ends you will still have your fruit in your pockets. There's a box on the island that items can be placed into and the items will be sent to the box located on the dock in your town. Fruit can be placed into the box. As long as the game doesn't require you collect fruit for the game, it can be taken home. The same applies for bugs and fish, but not flowers. Flowers can be taken from the flower game.
4. The card is a melody card. It's mail that can be sent to villagers and other players and it plays music.
I think it's 400 bells for one card.
I don't like taking photos in-game because I don't want to remove my SD card (had past issues). Picture is not the greatest: