MC calls it a "demon heart", but actually it's more a regular heart. MC was a heartless demon before who deserved being backstabbed and ganged up on as much as anyone.

All this brother and sister business makes it sound so incestuous.

Hopefully not. That "heart demon" is the only thing making MC semi-palatable.

Terrible MC, why should I care about how you end up. So far seems like someone who deserves a backstabbing.

Commander just sits back and let's them misunderstand a bit, ignoring the question they ask Commander as to whether MC is a enemy or not.

I wonder what the difference between captain and commander are.

So many innocent people to kill

It's fine if you're a spy but it's not fine! Which is it? Ash say's it's because of being caught, but till Ash revealed it to the inner circle, only two people knew in the first place which would not be a moral issue.

Camp outside rather than pay these fees? Also sneak in or something. Also does the adventure guild not help at all with this? It doesn't seem like Roxie even asked.

Author/artist sure looks for many excuses to expose Roxie.

I wonder if they could cast magic "chanting" with telepathy. It should be the same I would think.

You can just learn to cook.

When putting on a ice-pack you want something to be between the ice-pack and your skin so you're skin doesn't get too cold. AKA better to have the tights on. Also how long is she going to sit there, a sprain doesn't just disappear even with a few hours. And he wouldn't have a ice-pack with him. So better to help her home and then get the ice on her. Meanwhile the swelling would help immobilize the foot helping prevent further injury.

I don't know what he means by "put a compress on it", I am not familiar with such a item and search didn't come up with anything.

How did we get from helping carrying groceries to difference in behavior in school verses outside?

Why are you taking off your shirt to get your body temp? Those thermometers go under the tongue...

The old "rain makes you sick" nonsense. At least it's useful to the story in this case.

"handle" again that is a dumb concept.

It's not friendship power but just working together with regular combat.

Maybe the human monarch of North Korea turned into monster monarch? It would explain the orders to not choose a class. I'd also ask if there is something above monster monarch. Monster demi-god maybe?

Right, so many ways one can break this plot. Rather in no way does it work, this short story is nothing but plot holes.
Here is a possibly still incomplete list of issues.

1. You expect Erina to know all your friends, do you really share every inch of your life with Erina? They clearly pushed their way in. Erina clearly has the kind of soft timid personality that has a hard time saying no to people. Especially when three ruckus men show up insisting on coming in and claiming to be friends with your husband (the master of the house, in this kind of sexist setting, also because of the status difference between them) So the "Are you stupid?!" insult question really doesn't fit. Also not sure exactly who these people are but punching them seemed excessive. If it were for Erina's sake then insulting Erina afterwards doesn't fit.

2. If you just did something really bad to your wife, you apologize and make up with her, while never doing it again! Maybe couples counseling if that is a thing in this world. You don't try to have a baby or do experimental procedures on em. "I just had a fight with my spouse, we plan to have my memories experimentally transplanted into them so we cam mend the relationship"

3. You stabilize your relationship before you consider having children rather than trying to use children to stabilize the relationship. Children add stress to a relationship because it's alot of work to raise children from babies and conflicts over money and how to raise them etc.

4. If you believe your spouse has the mind of a 10 year old, you don't marry them in the first place. If you don't believe that is the case, you don't believe doctors spouting weird BS about how someone needs to be smart enough to handle labor pains.

5. As you mention there are many ways to have a child even if you believe this BS doctor. Adopting, finding ways to remove the pain, sleep through it, etc.

6. Memories is not the same as intelligent. And this is specifically a memory transplant. If the goal was to make Erina "intelligent" you need to find a way to make Erina's mind work better, not have more memories.

7. Transplanting memories might mess up someones personality and make things confusing for them as they might mix up which memories are real. Which might be especially hard on someone who's brain doesn't work so well.

That's a bit of a catch 22 though. Maybe he didn't really believe she had 'the mind of a 10 year old', she didn't believe so. It would be understandable if Alfea didn't believe that.

But then you would need to be willing to disregard any doctor who said nonsense like 'mind of a 10 year old means you can't handle labor pain'. Both because that's on the face stupid anyone should be able to figure out and not need to be a doctor, that intelligence doesn't help you handle pain. But also because if you really believed she had the 'mind of a 10 year old', you shouldn't have married her in the first place!

Also how terrible that you don't know your wife enough to know that maybe she does not have the mind of a 10 year old. Some marriage of love that you don't get to know your love at least to that extent.