Your wishes for a development plan

I find almost everything you write sensible, except for this part

In a building area with 20 plots on the outskirts of a village, I don't want to read that .... the greening of the roofs makes the area look so beautifully natural when right next to it the field begins.

I disagree. It is completely (!) irrelevant whether I build in the city or in the countryside, it has nothing to do with nature-like optical eco-feeling, but rather with the fact that soil is being sealed and a compensation is needed for that. How to achieve that has to be seen. Of course, a green roof is more expensive than one with roofing felt, but overall there are very many areas that are lost if they are not greened. And you notice that in summer, even in the countryside.
By the way, a conventionally farmed field is certainly ecologically less valuable than our greened garage.
But I know, when it comes to money, it quickly becomes "dangerous" ;)

A conventionally farmed field is certainly less ecologically valuable than our greened garage.

You probably mean an industrial farmed one. Conventional is actually what is called "organic" today, since industrial agriculture has only existed for about sixty years.

If soil sealing is a problem, no new development area should be designated. Moreover, I would like to doubt that the groundwater is actually damaged by sealing in our area - house, garden shed, garage will drain into the cistern, which in turn waters the garden - we have to make the paving permeable (as if a slope towards the garden wouldn't have been enough) The only thing that causes water to go the wrong way is the access road and the stupid retention cistern. A "green roof" with granulate and sedum is neither a contribution against sealing nor for ecology or species protection. We have such nonsense next to the office building for the garbage house and the bike shelter. It looks absolutely ugly and will never be nice. And next to the three-story concrete parking garage it also looks very forced. A natural green roof with real grass, on the other hand, will have small trees in a few years. Have fun with that

The argument of soil sealing and a [Begrünte Garage] is not quite clear to me. It doesn't matter what kind of surface is on it, sealed is sealed. It just takes longer for the water to reach the drain, in the end it still runs off, at least most of it...