That does already work of course. But is there a way to create a
real ".saver"-file which cannot be opened by everyone?
Why would you want that? It does not make a lot of difference for an
advance user to edit a .qtz directly or find inside the .saver bundle
(it's just a few more clicks in the Finder).
One another question:
Is it possilble to order the open parameters of a screen saver (The
settings, which can get adjustet by the user)?
I think the order is the order in which the inputs were published.