Raising a CSE does not delay your application though. All CSE communications are attached to your application and when a VO finally sees your application, he just goes through all the CSE that you have raised along with the application.There is no special processing required for CSE.
The VO doesn't just 'go through all CSE' =)). The case analyst now needs to verify all that new information and update it in multiple places. This may in turn lead to increased processing time and even an ADR.
I think the biometrics process speeds up the PR because it helps with background checks. Applications in countries with biometrics seem to be getting PPR faster e.g. Nigeria
This one is definitely not true =). I don't know what's up with super fast PPR's for Nigerian applicants, but biometrics requirement has no correlation with application processing speed. I provided my biometrics back in November, however, as of now, I'm at the same stage as everyone else from biometrics exempt countries.