Floor plan of a manor house with a gable roof, 170 m² living area

I also think that the door issue is somewhat underestimated in my opinion, because of 20cm display cabinets in the living room.

Furthermore, I would reconsider the arrangement of the children's room doors and the hallway size on the upper floor. I find a slightly smaller hallway in favor of the children's rooms nicer here. I would also align them differently so that cabinets can be placed behind them, which could also serve as sound insulation against the bedroom and bathroom. For the same reason, I would make the walls to the children's rooms particularly thick or similar.

Narrow doors are especially a problem when furnishing. As long as only Ikea chipboard has to be carried through, it’s no issue, but some people might feel the desire for finished solid wood furniture as they get older, and if the dresser doesn’t fit through the door and the window might not be accessible with a lift... then it’s frustrating. The only room I allow a narrow door for is guest (shower) WCs, because no furniture or large bathtubs ever have to be carried in there.

The raw structural dimensions for interior doors are typically 87.5 cm for living rooms (increasing to 100 cm, considering walkers), 75 cm for bathrooms, and occasionally 62.5 cm for storage rooms or guest toilets (for non-overnight visitors). In the passage width (the frame, i.e., with the door unhinged or fully open) you can subtract about 7 cm, so 10 cm for a door opened only 90° is quite plausible.

To annoy once again with the door. At least the door to the dressing room really shouldn't be a problem. The upstairs hallway can easily extend over the first step of the stairs and is therefore wide enough. And the gable wall should also be at least 2m.