Shouldn't a walk-in closet be accessible only from the bedroom? I think an access from both the bedroom and the hallway takes away closet space again.
The tip is meant differently: a walk-in closet should not be a trapped room of a bedroom, because in practice you then disturb the person sleeping in bed after dressing (light on/off, door open/close). Either make the bedroom accessible through the walk-in closet or make the walk-in closet accessible from the hallway.
Regarding the size of the children's rooms: 13.5 sqm can also be okay. But with rooms with sloping ceilings, it may be that prospective buyers like to only record the floor area of the room without stating the real living space, which is less.
Bathroom/storage: the utility room under the roof is a very small cubicle. Was the height of the knee wall mentioned? If the knee wall is present, then the washing machine should go under the slope and a roof window would also be a must in my opinion. However, I see the risk here, also in regard to the missing dryer, that the bathroom will be misused as a laundry storage and drying room. That would not be nice.
I find the pantry superfluous. Better to enlarge the utility room. I find the sliding door unnecessary – odors are everywhere in the house when cooking anyway, as soon as the door is opened once. And a sliding door also has to be opened. Then the whole rush of bad odors will pour out (with us, guests already know at the front door that there is something tasty). I also find the wardrobe too small. I assume: wooden stairs with open steps, underneath which there will then be a pile of clothes that can be seen from the dining area.
Regarding the guest room, is absolutely right with the example of grandma visiting. However, if it is only for a few days a year, you can arrange, and when grandma goes to bed, turn on the TV in the bedroom.
I read from the "either/or position" of the roof window that money is tight? I would rather do without a corner of the house and/or sliding door than without an additional window in the attic.
Basically, some information is missing, including the site plan, in order to evaluate, for example, orientations or window positions.
Browse through other floor plan discussions found here in the forum again. However, you do have to flip through quite a few pages to find the relevant threads.