Your satisfaction is also somehow a good that you do not want to jeopardize. If neither stairs nor windows are allowed to be changed, the scope is in my opinion limited only to the furnishings.
Yes, it is probably not much more than that. The business of the property developer is not to serve dreams shattered at the delta between wish and feasibility, but the transformation of building materials into affordable dream approximations. The compromises are as harsh as the field of servable customers is to be large. If low-income people are to have any chance at all and middle-income people are to come into the enjoyment of homeownership earlier, strict saving is unfortunately necessary. In this respect, I do not see a property developer here as the enemy of a "beautiful" but as a friend of an "at all possible" realization.
In the greater Düsseldorf / Cologne / Rhine-Ruhr / Rhine-Main area (as currently seen with Wilma at Krausbaum near CGN in ), such a "small" paradise is already a comparable effort to Tomek’s hipped roof bungalow in Brandenburg’s Jottwedeh.
One thing I honestly do not understand either is why the stairs are not turned at each floor exit. That would make the left wall after the stairs on the ground floor more usable, [...] and in the attic ensure that you do not have to walk into the sloping roof when coming up [...]
What possessed the property developer here to install a straight staircase in a house with only 10.5m depth is a mystery to me. The missing windows on the west side are also a mistake that cannot simply be remedied.
Regarding the staircase, the developer indeed deviates from the majority of comparable solutions here, but I consider the proposed additional window on the gable side to be unproblematic and successfully desirable.
The rotation of the staircase is basically off the table? Also a winding staircase?
I spontaneously immediately looked for the reversibility of the running direction (even before I wondered that there is here “quasi non-standard deviation” not only no second but no winding staircase at all). But a load-bearing wall in the basement speaks against it, which probably does not need to be discussed in the concert of the structural system of the house. A winding staircase would mean a special construction here, which in this case would probably also be a "logistics disruption factor." Apparently, the developer uses the same staircase model from ProHaus three times here, whereby I interpret the pre-stair landing between the first and second upper floors as a hint to the combination "underfloor heating on the ground floor with a modest floor height." Middle years of the house are not lordly years, one could say ;-)