Buy land, build a preliminary contract

Good day,

we have currently received the preliminary contract for a piece of land and would now like to have a soil survey carried out before the final contract signing. From your point of view, is this enough to be on the "safe side," or should other things be considered?

I have attached a few photos of the property; you can see the height difference compared to the existing property there. On another neighboring property, a part of this "bump," including the trees, was removed, and there was a massive movement on the existing property. So, is it unavoidable to leave this strip as it is, along with the trees that are already growing there?

I assume you know what you are allowed to build and that it matches what you want to build?

Yes, that fits so far. We have also already had various meetings with architects to discuss the development. What unfortunately no one has noticed yet based on the survey plans is precisely this strip for the slope stabilization of the neighboring property. As I see it, in this case I am paying for 2 x 19 sqm for an area that I cannot really use and can only remove with increased effort. In addition, there is the risk of movement of the neighboring property that I cannot really assess.

Then liability insurance - with the 38 sqm for the bag is annoying, but depending on the standard land value not so bad... for example, we have a driveway with 5 m width and 30 m length that is also not 100% useful. Also the 5 sqm behind our earthen embankment is only used for a hedge.

Regarding the strip, it should actually be clarified who is responsible for the height difference here!? If the neighbor has piled up soil here, he should actually support the elevation on his property and also bear the costs for it (e.g. L-shaped stones), or am I mistaken? But of course, one should weigh whether the 38 sqm are worth ruining things with the future neighbors right away. Whether some kind of grandfathering or similar applies here, since the slope apparently has not existed just for a short time, I cannot say.