Is there a way to see 'missed' scenes. I chose the wrong option with Rin and now I have "Love Life, Let Go". Is there a way to fix that without restarting the whole game?
Well, you could use cheat codes in the Computer during the weekends, which in your case would be "goodhomie" if I remember correctly.
There seems to be an indicator if you cheat though, so once you cheat then that playthrough will be marked. So be prepared to face consequences someday.
If you don't want to cheat, then you would have to start from the last save, where you can still get on Rin's good side, which is way back before the beach event.
Of course it isn't easy to fix things. You've already made your choice. How nice it would be, if we could just rewind time by turning back a clock. And another and another and another. That would be great, that's my wish and I will throw myself in the wishing well if it helps. Praise be.
If you're curious, I also had the same problem and I just decided to create a different save for that, since my earliest save (that's somewhat close) to the beach event already has the event trigger for being a bad homie, which uses the cheat.
(Also you can skip unseen dialogue, so it's not too bad.)