Your POV sounds too paranoid to be credible. You seem
to ignore the
fact that it's the way the ideas are expressed that is copyright not
the ideas themselves.
Of course, I don't want to deny the fact that people can claim another
interpretation of the copyright law and try to argue that additions are
derivative works. But that's just as like going to the police and
trying to convince them that the house of my neighbour is my house.
It's quite clear that as an initially copyvio
passage is more
frequently edited its resemblance to that text changes, and the degree
of copyright violation diminishes.
That's not the trick.
Additions are original works and the good way to do is to go back to
the sane situation, to erase the copyvio text and to re-add everything
that is not directly based on it.