Am I able disable new changes for a G+ post?
Say I post an image on G+ and somebody writes a really bad comment. I want to "conserve" the comment (disable new changes like deletion or editing of the respective comment) so I can show it to someone.
I don't see how. The person who wrote the comment "owns" it and will be able to edit or delete it. You can probably only take a screen shot. Better would be to report it as abuse.