Bernd- The PF replication engine isn't safely compatible with CCR. You should NOT have CCR enabled on any PF Database in your org if there is more than one PF Database in your org. The reasons are rather complex, but we realize there's a reason to have both enabled: when you're transitioning (ie, you've got 1 PFDB using CCR, but now you want to add another PFDB). In this case, the config is allowed, but for proper reliability, you shouldn't leave things configured this way for any longer than is physically required.
Marc- Yes.
Paul- 1) correct. 2) no. Charlotte's response is misleading. The script only changes replica lists. You absolutely need to wait for the whole replication process to finish. See the revised article to see how to know when it's done.
ilantz- Yes, there is. :-)