I think it would be a good idea to remove the "Know your rights" part. Users switching from the firefox branding may be doing so with an expectation that they will not have Mozilla popups appearing anymore (even though this is much better than the previous situation). Most of the paragraphs in about:rights start with "Mozilla", and I can't see the benefit in having it around. I think an acceptable solution would be to leave about:rights accessible (in case abrowser users are interested), but remove the "Know your rights" part. This is how the situation was with firefox before Mozilla got involved, anyway.
I think it would be a good idea to remove the "Know your rights" part. Users switching from the firefox branding may be doing so with an expectation that they will not have Mozilla popups appearing anymore (even though this is much better than the previous situation). Most of the paragraphs in about:rights start with "Mozilla", and I can't see the benefit in having it around. I think an acceptable solution would be to leave about:rights accessible (in case abrowser users are interested), but remove the "Know your rights" part. This is how the situation was with firefox before Mozilla got involved, anyway.