Floor plan single-family house, approx. 130 sqm, single story

Our family experiences with bungalow and basement are that the basement always gets fuller and 90% of the stuff and old furniture are never brought back up. That is why our decision was to have the bungalow a bit bigger, 125m2, and no basement. In the mentioned 15 years, the basement gets full.

In the mentioned 15 years, the cellar will be full

No problem, then you write in the calendar to start decluttering in twelve years :)

Clearance areas must still be observed in my opinion, even if the building envelope provides otherwise. 2.5 m is too little. The driveway to the garage is also too short. In my opinion, it must be 5 m. Or does the development plan say otherwise?

Setback areas must still be observed in my opinion. Even if the building envelope provides otherwise. 2.5 m is too little.

The driveway to the garage is also too short. In my opinion, it has to be 5 m. Or does the development plan say otherwise?

hm, I have drawn the garages at the edge of the building envelope, that is about 4.30 m to the street, so I probably have to set them back a bit. The development plan only states that garages outside the building envelope are not permitted, but that does not mean that other regulations do not apply...
I have 4 m to the (only) neighboring property boundary, that should be fine. The 2.5 m is to the street and the existing bungalow is there now as well. But that no longer means that I am allowed to build like that again.
Thanks for the hints, I will add them to my list of questions.

The 2.5m are to the street and the existing bungalow is there now too. But that doesn't mean I am allowed to build like that again.

In most federal states it is 3 m (or 1/2 h), which can extend up to the middle of the adjoining public street space. The building window marking with only 2.5 m distance to the boundary is therefore not a contradiction in this respect. Garages require 5 m distance in front of the gate in many state building codes, so the distance garage/street also depends on which side the driveway is on.