If we played with RAW CP/IP, my players would be dead or drooling in under 10 sessions, I'm fairly sure. So.. I hand them out based on the solid mechanical foundation of "when I feel it's appropriate", and we usually discuss more elaborate consequences by email before introducing them at the table. For the sake of roleplaying and suspense, I'd suggest that's probably the best way to go about it.
I also let my players get rid of both, if they can come up with a compelling story explaining how. This too is handled by email usually, and tends to involve long in-fiction periods of downtime.
Over a prolonged period of time (campaign arcs of twelve to fifteen 6-hour sessions) I've had PCs reach 30-40 CP. I don't use many Daemonic creatures. I do, however, throw in CP for poor moral choices, choices that can be damning even if not connected to Daemons/the Warp, usually one or two points.
Had a Guardsman with an imaginary friend. Named the guy and everything. Once, when asked if their way back was secure, he answered by saying "Zeke's got it covered." It wasn't until much later the other PCs realized there was never any Zeke.
That's funny, one of my players did exactly the same, tough his invisible friend was called Zack in homage to a video game (I forget which). He managed to come up with the idea and run it by me in 2 mins alone during a break, so between us we managed to keep the nature of Zack undiscovered for.. 2 sessions, I think.