Hello there,
Since the only ones requiring follow up are 3 and 4.
3. I have already explained the concept behind which this is not implemented which is to keep the events to happen around the characters where they are doing their own thing and you go to them, instead of being a "checklist" of calling the girl for a booty call. Nobody said Himari ran the business alone, I said she wouldn't just leave her work for a booty call. And all the topic in regards to this is null since Starmaker is not a day time divided game, theres no morning-afternoon-evening, so there will always be moments where the Anna case happens. Since you need more explanation on Anna being at the beach and then at the flower shop, you can say she was taking a break. I still don't see the "booty call" for something else than... "I want more scenes in the way I want". I said it before, instead of using a phone for it it was decided to make the mc go to their locations.
4. Yes, you can just save before you do something, of course you wont know on your first playthrough but thats something thats normal. You are not supposed to know what a route has or doesnt have.