Newly built single-family house approx. 220 sqm, 2nd design city villa

Take a look at the model home parks of Hanse Haus in Hannover Langenhagen. Not perfect, not exactly tailored to you, but maybe it helps.

I had already written that I would separate the two seating areas Kamin/TV. Then you can use them independently.
I’m not sure if it won’t be too tight.

Don’t present a floor plan to the architect. Rather, a stack of Pinterest pictures and exact specifications. Like the kitchen needs X meters of work surface.

Why can't sitting comfortably together and sitting in front of the TV happen on the same furniture? Independently, they cannot be used in the current floor plan. As a replacement for the balcony on the upper floor, I believe a utility room has already been suggested to you so that laundry can be done on the upper floor where it is generated.

We cannot change the orientation of the house.

You can change the house, but not the plot. Why not simply adapt the house to the plot? For example, making it "a bit smaller" near the property boundary can create some space and thus, with a bit more distance to the border, you can also plan a nice sunny side. You can supply the house with sunlight by, for example, installing a large window in the secluded kitchen. And then of course you want to have direct access from the kitchen to the terrace... for grilling, drinking coffee, sipping cocktails, preferably on a simple, short route. And if the G-shaped kitchen is so practical, why then go from the walking snake to the Nikolaus house? It doesn't have to be a G, but a U-shape would be clearly better than a K-corridor.

Of course, we will get a professional. However, we do not want the architect to draw 10 drafts at the beginning of our planning. Therefore, the rough direction should be known.

Honestly: Your basic idea in the layout is nothing special. It just looks like it was slapped together in a way that is somehow incomprehensible coming from you as a layperson. Standard, but partly bloated without harmonious transitions. A really good architect can do that much better – they have much more knowledge about how to divide things in a chic and great way instead of just big.

Three balconies due to the exterior views as I wrote: there was one above the entrance, one above the terrace, and the one from the dressing room.

If the exterior views are no longer accurate (the dormers are also removed), then please omit them as well, it only causes confusion.

If the money isn't enough, we can always downsize

So where exactly is your budget? That's fundamental for the discussion here.
It's not productive to discuss another 20 pages here and then you come up with a budget for the house of 400k. What you are currently planning is just under 600k + ancillary construction costs + land. Does that work for you?

Depends on the situation; here in Bavaria, 600k would by far not be enough