160 sqm hillside house / floor plan optimization

A nice design for a small family who can live without much "stuff," as storage space is limited. I like that and have also been living with limited storage space in our house for about 1.5 years. It does us good not to overwhelm ourselves with things. I like the fairly private area for the child – the more independent they become, the better such a setup is. I can imagine that a "city villa hat" would not suit the house much. A slightly pitched shed roof, which brings a higher ceiling height on the south side, could give the house a special pep. You could also play with tall bands of light there. For this house, I can also very well imagine a somewhat raised parapet and flat roof with a non-visible photovoltaic system oriented primarily to the east.
Here are a few more thoughts:

[*]The entrance hallway has a lot of square meters yet little space for a coat rack. --> high construction costs for little utility.
[*]I would reconsider the living area – why do you want to sit with your back to the window, especially since there is a TV room? Better to look into the garden than at a cupboard.
[*]Consider installing another window in the living room; you can never have too much light and can block it out on very sunny days. Possibly also make the middle pane in the living room a walk-through opening to the garden – lots of fresh air many months of the year contributes to quality of life. Instinctively, this would also be the place where the "running routes" lead outside most frequently.
[*]A window band above the bed provides morning sun.
[*]Furnish the guest room to see how to get past the bed to the technical room. I would possibly also make access to the technical room from outside (directly or through the storage room). From experience, I can say that is not a practical disadvantage.
[*]Who uses the TV room? With a teenager, it could cause noise conflicts at bedtime.

Have you planned for a child or is the children's room just leftover?
If you have planned for a child, I find it inconveniently located.
I would plan it with the TV room — meaning the door would be in the private area.
Always passing by the entrance in pajamas is not so nice.

The rest has already been pointed out by others and I can only agree.

But isn't it strange if the staircase entrance is practically in the middle of the room?
We chose the recessed entrance so that the house looks somewhat "special" and "more open" from the outside. This is also highlighted with a different color

The more often I look at the floor plan now, the less I know how to remodel it

I agree with most of the objections here: child left out, wardrobe with the stairs is disharmonious, downstairs looks very cramped
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What I think is great is that you planned right away with the terrain and the slope. That is already the best way to enjoy life with the house and garden. Many forget the garden and only plan a balcony on the upper floor...

I would like to try something. But your posted photos seem to be nothing more than screenshots: I can’t read any numbers properly on the screen in the separate window. Would you like to upload everything again in higher quality?