You would like to have American built-in closets - I also think that's great. In the implementation, the architect confuses that with a dressing room. Americans no more think of changing clothes in a walk-in closet than Germans think of cooking in the pantry. This requires a bit more communication about what you roughly mean by a "built-in closet modeled after the American style." Neither of the drafts I see succeed in this respect. The architect’s draft doesn’t because she plans dressing rooms for children, and yours doesn’t because it doesn’t integrate the dressing rooms space-savingly into the architecture, but simply takes some space from a previously usable room.
The living area is exceptionally spacious, and there is something special about placing a living room setup in the middle of a room instead of against the wall. That is an absolutely understandable luxury for me. The sketched arrangement is still somewhat small for the room unless you want to accommodate a harpsichord or something. If the construction costs are so burdensome that the furniture later has to come from a discount store, I would refrain from that. If already, then properly.
The way you place the dining table seems to indicate that this spot has no central importance for your family life. The tightness around the table stands in a strange relationship to the possible spaciousness of the kitchen and living area and is at the traffic triangle of stairs, hallway, and living area. I don’t like that stylistically, even if it works.
And then there is a pillar just standing somewhere. That looks completely randomized, although it is certainly beneficial statically and saves costs. But if I already shy away from statics costs, then I would wish for a solution that has a living function and not just some random pillar on the way from the dining room to the kitchen.
Thank you for your detailed contribution; there are some good suggestions in there. In fact, I haven’t found a good example on the internet for the dimensions of such built-in closets yet. I only ever find floor plans without measurements.
In the living room, I would also like to have a piano behind the sofa on the empty wall. You hit the nail on the head with the dining table. We very rarely sit at the dining table. Every few months there is a big game night with friends. But otherwise, the table is used very sparingly. I don’t find the solution with the bench perfect either, but if the table is freestanding, it really feels a bit too cramped near the staircase.
The pillar is indeed only optional. The architect said it might be necessary to put one there and had penciled it in. But whether and exactly where it will be is something a structural engineer will have to decide later.