The author loses/tricks the readers, not writing about the main plot arc, the Goddess's request to assassinate the "hero".
Main character deepens intimate relationship with Dia (without any plans to get married with his cousin/half-sister). Is incest/statutory rape with a family member a crime in the US/Japan/Canada?? (Yes.) Does a person that in mind and body does not exist on Earth, guilty of sexual crimes toward minors? (universal declaration of human rights protects minors from criminals and crimes (anywhere, that is why it is "universal").) Is it a crime to promote in light novels, sexual crimes to minors? (yes).
The main character and his retinue is increasing the products his "fake front" company sells. Main character improves spells (team is able to mutate to animals) and weapons his retinue uses. Main character desires harem lifestyle with his retinue (cousin, aide, and employee-manager).
Main character (assassin) wishes to be able to fight and defeat demon monsters. With improvement in level and type of spells, and stronger weapons and ammo, is able in volume 3 to fight and defeat demons in this alternate reality world. Was he hired to hunt down demon monsters? (no.) Is this a requirement of the Goddess? (No.) Why? (maybe because he has nothing else to do, since he doesn't really intend to assassinate the "hero" in this 3rd. volume.
Main character is not yet a noble, his father is the noble, main character is still now the "son" of a noble. Because of this, isn't it impossible for him to become a Knight? Doesn't the main character need to inherit the noble title?
It's an alternate reality world and the author seems not to worry or care about making it real or logical. I feel the light novel is not going anywhere. What point does a story have if it has no point, rules or plot advancements?