House floor plan (access via slope)

Hello,
we have now purchased a 505 sqm plot.
It is located on a slope about 2.50 m high, after which the plot is almost flat (2m incline over the 25m length of the plot).
See self-made ROUGH location sketch: 3D-Lage_nur-grob.jpg
The width of the plot is 20m, the currently planned house width of 8.5m is already the possible maximum.

Development plan/Restrictions:
Plot size: 500 sqm (20 x 25m)
Slope: embankment at the entrance area, then almost flat.
Edge development: no
Number of parking spaces: 2 (normal garage and carport (l=650cm) planned side by side)
Number of floors: (utility room) basement, ground floor and upper floor (knee wall 120cm)
Roof shape: gable roof 35°

Client requirements
Number of people, age: 2, just under 60
Room requirements on ground floor, upper floor:
On the ground floor guest room, living room, kitchen (kitchen and living room separated by sliding door!), guest bathroom with shower.
On the upper floor there should be 2 (or 3) rooms, plus bathroom.
Office: family use or home office? Partly, planned on the upper floor at the gallery (or in the guest room on the ground floor)
Conservative or modern construction style: rather conservative
Open kitchen, kitchen island: No open kitchen, kitchen island: yes!
Number of dining seats: 6 (max. 10 for parties)
Fireplace: no
Music/stereo wall: rather no, nothing big
Balcony, roof terrace: only terrace on the garage next to the dining area planned
Garage, carport: yes, yes
Utility garden, greenhouse: no

Note:
- The entrance door must be located roughly where it currently is due to bridging the 250cm height (embankment)
- The basement has a ground-level entrance door (laundry room, workshop).
- The width of the house is limited to 8.50m.

House design
By whom was the design created:
- Architect: yes, basic idea from us

What do you particularly like?
Everything on 65 sqm on the ground floor "accommodated" (bathroom, kitchen, stairwell, living room, dining area)
Hallway with built-in cupboard in niche, also refrigerator and oven recessed a bit in a niche.

What do you not like?
Are there enough "walls" for cabinets available?
Is the dining area large enough for up to 10 people (with extendable table)?

Price estimate according to architect/planner:
...
Preferred heating technology:
Geothermal

If you have to give up something, which details/extensions can you do without:
- "Sleeping" on the ground floor could be a bit smaller (to 12 sqm)
- "Sleeping" on the upper floor could be smaller (currently 18.7 sqm)
Cannot do without:
- Living room and dining area must be separated by sliding door!
- Guest room on the ground floor (also as a fallback solution if one has problems with stairs!)
- Kitchen island,

Why did the design turn out the way it is now?
- Our wishes were implemented, e.g. niches for wardrobes in the hallway and kitchen (for refrigerator and tall oven)
- On the upper floor two walls at 45° to loosen it up a bit,
- open gallery on the upper floor (which could also be closed with drywall)
- In the basement near the basement door space for 2 bikes
- Carport easily accessible even with camper (650cm long)

What is the most important/fundamental question about the floor plan summarized in 130 characters?
Are the rooms (living room, dining area, kitchen) big enough or too "tight"? But it is only 2 people anyway.
Is the bathroom with shower (90cm) sufficient? Also for later if care is needed?

Is there also a north arrow (or did I overlook it)?

Why do you make this elaborate entrance to the ground floor and don’t treat yourselves to a grand, ground-level entrance area in the "basement"? Properly spacious with large windows, with a cloakroom and all the bells and whistles. You have to go up anyway, but that would be easier/nicer inside the house, and you would have more space for a terrace/garden on the ground floor.

Access via the basement was also discussed, but since it is a utility basement (without insulation), this would involve five-figure additional costs.
Also, access via e.g. 5 steps, 1m flat, 5 steps, 1m flat, 5 steps, ... is less strenuous.
And you wouldn't really gain much space in the ground floor hallway (OK, the "built-in closet" of 120cm x 50cm would be eliminated).
But main entrance in the basement is not an option.
And the "elaborate" access to the ground floor, which anyway is "lost" space, does not take away from the usable garden or terrace areas (in the southwest).

North arrows, sorry, that's correct:
North is roughly "bottom left" in the pictures, see here two pictures with north arrow

Because you are asking if 10 people can also fit in the dining room. That will be pretty tight with only 37sqm for eating, cooking, living. Because you are forcing a bedroom onto the small floor plan. Due to age and the justified desire to be on one level, wouldn't it be better to build a bungalow on the basement?

Because of the slope, a basement is necessary or cost-effective, otherwise yes: It would have been something without a basement.

I would not want to put myself through this "hike" from the (too small) garage to the front door around the outside! Groceries will surely be carried through technology/cellar.

Space for "eating" is a bad joke. That looks like a 49 sqm apartment to me. And if an architect places this closet in the sleeping area in front of the bed, I would start to worry.

I would never build (or have built) it like that for the many euros!
A clean, better solution is needed.