It might be just me but I never found Japanese stories ever do the whole misunderstanding and regret plot in a satisfying manner. Maybe it is because I have read too many Korean web novels and they pretty much perfected that type of story (although can be over the top sometimes).
Most of the characters personality's as well as the plot got butchered one way or another. You can already see this with happen with Serena. Having Kania figure out Frey's identity and triggering the penalty at night caused a huge plothole which means other plots points like Serena's memory...
The world is run like a software, it isn't just the system. Even the way the deities influence the world is by writing codes. It is explained later that the reason it is like this is because the goddess who created this world is very eccentric.
Every time a story starts out, people expect it to provide all the answers immediately instead of just having it told as it goes along. As I said before, the time travel part all gets explained later. I don't want to give in to much detail as it would spoil many other parts of the story but if...
All of the stuff you written gets explained later. This is why people should stop being so impatient, expecting everything to be spoonfed in the first 5 chapters or so of a story. To answer your question as to why Frey doesn't just pick the ordinary route and leave some people to die, it is...
Because it wasn't a nightmare, it was something they actually experienced before regressing. Also he has (in their view) already have done many bad things in this new timeline after his mother's death.
I like to think myself as someone tend to be very forgiving when it comes to manga/webtoon/anime adaptations cutting content from the source material but even this one is kinda outrageous. It isn't just a few events/monologue getting chopped off due to constraints but entire characterizations...
The issue I have with the FMC is despite causing such trauma to the MC, she pretends to act like everything is all normal when they meet up again and then proceed to hide the truth dragging out the series. You can say her lying about that incident is just a character flaw, but clearly the way...