Dance Moms is not a staged performance. The events are based on real time and no stage rehearsals. On the other hand, some people claim that it could be staged. However, there is no proof to these speculations.
Well, I saw in an interview that Abby & Cathy are actually really good friends. So, I think some is but some is not. For example, I think (this was like 5 episodes ago though lol) that maddie's music didnt purposely skip but, they scripted Kelly & Christi to say that Abby cheated for maddie. Hope I helped(: