No information from the building authority to the property owner

In the 34er there are only special cases.

No, no special cases. Not a single one. Merely - or fortunately - a lot of flexibility.
In the 34er you can submit 198 or more preliminary requests. Always about concrete questions and designs. That makes absolutely no sense. Unless one asks whether a single-family house can be built detached. Which still does not necessarily mean that it really helps the interested party.
Because the 34er provides maximum flexibility - I do not want to be restricted by a preliminary decision that does not specifically help me with the house I actually want.

Who wants to move from a city with all urban amenities (starting with local supply, shopping, culture, nightlife, recreation, and ending with educational institutions and jobs) to a cow village?

A growing city like Leipzig exerts an increasing pull on the surrounding area every year because even in a big city – oh wonder – housing options cannot be expanded indefinitely. Besides, you also have to be able to afford living in the big city (although there are supposedly people who spend 50% of their income on housing). I also never said that people want to move FROM the city TO the countryside. My wife was born in Dortmund and lived there for 27 years, I come from Schkeuditz, we currently live with our daughter between IN and R, but for us a big city would never be an option as a place to live again. And for someone who now has to move away from the countryside because of a job located in a big city, nothing might change since they had to commute even before. On the topic of quality of life city/village you can ask 10 people and get 12 different answers, which leads nowhere. As I already wrote, the property is in a "cow village" with 20,000 inhabitants, the population has shrunk by 0.1% (that’s 20 people!) in the last 5 years. The city doesn’t have a theater, but it has a cultural center, all(!) types of schools and the most important specialists are present. Within the city limits(!) there are 24 restaurants and bars, which might be too few for a habitual drinker.

are you planning to hire a real estate agent for the sale?

No, that has already been ruled out by my father (he has a "problem" with the professional image of real estate agents).

Because the 34er offers maximum flexibility - I definitely don't want to be restricted by a preliminary decision that doesn't concretely help me for my specifically desired house.

But you don't lose that just because there was a preliminary inquiry, or am I seeing that wrong?

Honestly? If there are detached single-family houses and two-family houses, etc. around it, then why is a preliminary building inquiry needed for a detached single-family house? The inquiry is, to put it mildly, pointless and has no added value for the interested party.

Honestly? Maybe you know more about the property. So far, I see 1100 sqm and then in the worst case 14 m wide. The seller is dreaming of a semi-detached house (and will base the property price accordingly).

Anyone who accepts that as a private buyer, based on rose-colored glasses, is not all there. From my side as a buyer, there would be an additional clause in the purchase contract: the seller guarantees the possibility of building a semi-detached house. Let’s see if the seller would sign that...

And all of this over 125 euros in fees, and a bit of work for the authorized building submitter.

Without prior notice, we would not have bought our current plot

It is not a question of whether one should generally submit a building inquiry, but whether the seller has to take care of it.

As a buyer, I would insist on an approved building inquiry.

Why? Maybe you don’t want to build what was requested? You have so many possibilities in the 34 area. No matter how well-meaning the seller is – I’d rather inquire myself.

But it won’t be taken away just because there was a prior inquiry, or am I seeing that wrong?

I already said: many are deterred or intimidated. How often do I read “Building inquiry for semi-detached house positive” or “Single-family house with 120 sqm gable roof positive.” But you don’t want that. What is a young family supposed to do, who hasn’t exactly “followed the forum for 3 years,” if they don’t want a semi-detached house or 120 sqm?

In the 34 area there are only special cases.

No, it’s the other way around: you can go wild with design and shape in the 34 area. You can build your special case there.

The “general settlement development” applies (whatever that means).

That means that something like

Information about the floor space index, site coverage index, DN, number of full floors and the building window/building limits will be provided.

will not be given.

1,100 sqm plot,

The plots are between 65 and 80 m deep.

The question an attentive reader should ask here is: how wide is the plot? 13.x or 17 meters? That already limits the wishes. But the interested builder should and wants to realize their own ideas, not those of the seller. Regarding the location: as I understand it, the plot is a 10-minute drive from the infrastructure until you reach a train station that takes you to the city of Leipzig. A typical commuter situation for a family with 2 cars. Certainly not uninteresting for one or another. And a few can also be happy with 13 meters width. However, it is questionable whether one is willing to pay the same price per sqm for the full 80 meters.