But is it necessary for QM that the observer can process his obsveration? I mean, i already read discussions about that in other forums and physicists seem to not agree on those parts. But im not educated enough to judge there.
I don't really understand what your asking in the second question? What are you referring to when you say two observers, observe the same things (in plural)?
I'm guessing you cannot be talking about a QM measurement, because each QM measurement is independent, and irreversibly changes the state of the system, such that you can't make two measurements of the same thing. So when you say two observers observe the same thing, it doesn't make any sense from a QM perspective.