Too many questions. 1, So far as I know if you visit Sakura during the day and do chores she can invite you to come back later tonight, which seems to guarantee you get the sakura/sarada version rather than sakura's wine date.
No idea what you are talking about with Sarada.
Himawari's 'fly incident' scene can ONLY bet set up on the very first day of the game. You have likely missed it. You CANNOT just unlock it later on. Think of it like the snacks you can buy on day 1 of the game are super special ones that are only available then. You likely should look for and read the guides.