Design for a single-family house with 160-180 sqm - suggestions for improvement?

As far as I understand, you are not allowed to upload the plans due to data protection and copyright. Therefore, I redrew them myself

Then you misunderstood something! They are your plans, if you paid for them, they are your property and you can do whatever you want with them. It only becomes relevant for data protection if personal data is visible on the plans, which you are not allowed to share without the consent of the respective person. Floor plans are not personal data. It’s not like the address is in the middle of the living room floor plan. Take a screenshot and crop the floor plan tightly so that no personal data is visible anymore. Otherwise, you really cannot be helped. By the way, that’s what I did too.

That's exactly right. I don't see any chance to help properly this way.

Living area already in the south. You rarely see that here lately...

Please draw the doors and furniture correctly in the hand drawing. (this should be done anyway, only then can you tell if the rooms fit. 2x 1.5 m wide sofas or a large XXL living area makes a difference) Your bed is only about 1.5 m long, many doors are 50 cm wide and the chairs are 25x25 cm if 1 cabinet is 0.5 m.

Does this help more?

Just take a photo of each one individually, include all the measurements on it (because without them many simply cannot be evaluated).

At first glance, I find both the hallway and the living room unusual... hallway has way too much wasted space because of the stairs, living room could seem tunnel-like. But without measurements everything is hard to judge.