Help with floor plan design for single-family house

What do you think, does a house measuring, say, 12.5m * 8.8m still look good and is functional, or does it become weird? I myself hardly ever see it from the side...

If the architect suggests something like this, then that's already half the battle :)
Go along with this idea, an opinion.
I am looking forward to his design!

In this paragraph alone, you say 3 times that bay windows are not necessary.

Well, who was drinking when you already read that dropplet?

It says that making the bay windows without balconies would be cheaper (I would rather say, less expensive), and that they are dubiously necessary.

I even go further and have already claimed: a) they wouldn't really allow that much "additional height" and b) certainly not, since they approached a zero-sum game, if you use them as balconies = thus generating even more attic square meters.

Get rid of them because they are expensive and inefficient and just pure luxury for "the cigarette afterwards."

2) Due to our family situation, we need a spacious room on the ground floor (I call it guest) complete with a fully functional bathroom, low-barrier.

I assume that a customer is disabled? I would think about this room location. On the one hand, it is quite far from the living area, which of course can be advantageous because of noise, but has the disadvantage that the resident might feel somewhat excluded. We don't know the degree of disability, but just as a thought exercise for you. Also, the south-facing location may not necessarily be advantageous for bedridden people because the room heats up too much. Perhaps a location next to the living room would make sense? Also, 's post about barrier-free construction made me think that here there are also two doors (stairs) that isolate the room from the rest of the family. I would keep everything open and free. I would move the garage further forward and remove the utility room passage. I would probably line up the slim version along the entire west side with living room, dining (opposite the stairs), and kitchen (NW), and design a room in the NE with a terrace door to the west, barrier-free. Shower toilet then below the stairs.