Floor plan design for a single-family house for 4 people on a 390 sqm plot

Merit badges - You obediently heed my stone mantra ;-)

Does he mean that it is too tedious for him to cover the walls every evening after work?

You are supposed to be content with a maximum of 25° DN. Let's assume you would exploit the recommended minimum slope of some roof tiles with 21° DN, then a house of equal size at 10.30 x 10.30 m could still have two sides of unequal length measuring 9.35 x 11.35 m - nicely as a hipless pyramid roof. This does not necessarily force a square format, which is always a constraint for a floor plan (at least under 150 sqm of floor area).

Do I understand correctly that you are aiming for a suboptimal sofa position or living room furnishing for a seating window instead of a sofa where several people from a household could comfortably sit to look out into the garden (if it were planned properly)??? I would say that a reset to Pinterest and super wishes in the head should happen here to then find the comfort that should at least be there, and not blindly plan a nice-to-have for which there is actually no space and which just senselessly moves in next to the sofa pushed into the corner.

The same applies to the fireplace: I agree with BU that with a tent roof you should not take the exterior walls. Nevertheless, where it is now, it is a nuisance in every respect. That is a folly. It is in the wrong place. That is a path that is walked several times a day, at night etc. Either it is planned differently or it should be fundamentally questioned. My opinion. Especially since with this sofa position it is not usable at all because the corner gets too hot, or will it be an ethanol/gas fireplace?

Maybe you can still turn the sofa somehow,

I think it's good that you have your detailed wishes. If the seating bay window is consistently designed and comfortable, there is no need for a corner sofa - and the "space issue" is solved.