You can probably find single examples of all of that above

Here's an interview of a student about how the state tries to break the protests.

Exmatriculation might be quite rare. But the Staatsschutz telling the BAMF to revoke visas, based on Facebook posts most certainly is not. It's just not the kind of things you're gonna read in the SZ, or Welt.

This "stance of the state" thing is not law.

Yes, because the German constitutional court wouldn't allow that kind of law. It is however a soft-power tool to shape political discourse in favour of Netanyahu.

There were for sure public discussions about denying citizenship for people who oppose democracy or the right of Israel to exist.

I findeyour faith in the organs of the state a bit naive.You can check out yourself how these decisions not to grant citizenship are carried out. If you ask me: most of the questions the judge uses to determine whether or not someone is "opposing democracy" wouldn't get a correct answer from most Germans.