Sorry, I did not get around to measuring things properly. But for sure no grinding halt or any other problems.

But I had the impression that Email and Alarm Clock start running again by themselves after I killed them. I need to double check. If there is a "keep alive job" that makes sure certain applications are always up and running, then killing them would be pointless. If that's really the case we need a configuration option to permanently disable applications we don't need.