What I don't understand is that he likes her but when he saw there at the student council, he called her puke girl rather than by her name. It wasn't as if he hated her enough to try to humiliate her.
If you're so tired that you collapse to the ground, walking up a flight of stairs to get to sit on benches is not good suggestion. It didn't seem like they were carried up those stairs either.
These random minor antagonists are really stupid but also the privacy of this organization is whack. We know that the guild takes a massive cut from drops in dungeons so a frequent adventurer should've been able to piece together that nothing they're doing at that level is going to be...
I can't tell if the manga should be taken seriously because this magic system makes no sense. Breaking into someone's castle to try diplomacy is also ridiculous.
That's a pretty big tax to pay in cash, but at the same time we don't know how much those stones cost. You should be incentivizing people to enter your dungeons not driving them away.