Maybe means probably, it depends on several factors.
That's right.
Is "Freizeitgrundstück" even a legal term like "Baugrundstück"?
No. It is often used by real estate agents to make undevelopable plots appear attractive.
Let me explain more precisely what I want: Ultimately, I want a plot of land on which a small recreational house/garden house/holiday home made of wood stands (1 room).
That will be difficult.
First, you have to clarify the planning law (§§30, 33, 34, 35 Building Code). Is the plot even buildable and if so, how (this is then regulated by the land use ordinance)?
Are there additionally local statutes that restrict your project? More and more municipalities are moving to prevent the creation of holiday apartments by statute because of the housing shortage.
If your project is permissible on the plot under planning law, the building regulations hurdles apply: traffic-related access, supply and disposal, fire protection, thermal insulation, structural stability, clearance areas, habitable rooms, ...
For building land, by the way, there is a building obligation which can even be enforced by the state.
Yes. I assume you are referring to §176 Building Code. It is often used for threatening. In practice, rather a blunt sword, because very very difficult to enforce.