It's possible that they're actually trapped in a limbo, so even if they get out of the loop the only thing that awaits them is heaven (to put it nicely)
The other heroine's father is not actually a bad person. He didn't even know that the woman was pregnant, and no one forwarded any of the letters he received while he was essentially banished to the outskirts.
I just compared volume 8 and the numberings in Mangadex is definitely off. (Volume 8 chapter 34 in tankobon is definitely way past the encounter with the elf.)
This series should either remove the volume numbers to match the official raw numbering, or fixed entirely to follow the tankobon.
That'd actually be a good ending for them. The girl has been trying to find a way out for hundreds of years at this point (not sure how long it's been for the boy though).
Gyarus are often paired with otakus (hence the "the gyaru is kind to the otaku" genre). But the girl doesn't seem to be an otaku, so big difference there.
NPCs in games can retrace all of your steps (or get stuck but somehow can teleport right next to you). They need to be extra careful while traversing the underworld because Ada and Kiira are real persons, not NPCs.
Having attractive and likeable characters always goes a long way. It's really hard to get invested in the story if there are no characters that you like.
Probably not, but that's just Ruomen's personality. He always thinks logically and never acts on assumptions. To top it off, he has no ambitions, so he just let others exploit him to no end.