Single-family house floor plan discussion, opinions welcome

Not productive, Karsten. The OP might have needed to tell the planner who lives there. The house would have looked different.

My feeling tells me that help is not wanted here anyway, only confirmation that everything fits.

Personally, I find the upper floor, even with only one child, poorly thought out.
The ground floor is just standard, that works. Kitchen/dining area at the main terrace as the focal point, living room more separated would be the more modern version (and I also find it significantly better, but that is a matter of taste).

My feeling tells me that help is not wanted here anyway, only confirmation that everything is fine.

Your feeling deceives you, I am very grateful for your criticism. I only got back home this afternoon, had no time to comment and read yet.

We will probably move the stairs back up, which will allow the traffic routes to be reduced and the rooms to be enlarged. Where we will then realize a proper wardrobe is still up in the air.
We will then reduce the bathroom and enlarge child 2’s room.
In our opinion, the dressing room is not that big. We saw it like this during a house viewing and found it optimal. [emoji2]

Whether the effect of

this can reduce the traffic routes and enlarge the rooms.

will really be from

We will probably move the staircase back upstairs,

I doubt. The staircase is just fine as it is now. On the one hand because of the centrally located exit, and on the other hand because with a moderate knee wall it is always better to move the staircase away from the eaves wall.

Where we will then realize a decent cloakroom remains to be seen.

... and otherwise, the more extensive the changes are, it probably won't stop my complaints to just two small points. Now this will not be my house, so that is not the standard, but: if I check off little "red" or even say: "fits. build it like that," then not much was done "wrong."

For a moment, boldly assuming, that would also mean objectively that one is close to the optimum; the reverse conclusion would be: every change then takes you further away. At the North Pole you can only go south ;-)

I find the staircase position very good like this, have a look at Eco3 from Heinz von Heiden or Vario XL 2.0 from Massivhaus Mittelrhein.

But what is to become of the 2 storage rooms on the upper floor?