I believe a bigger drain on the battery is the LCD monitor.
Turning this off will have a bigger effect on battery life than
disabling full-time autofocus, I think.
I don't like having the LCD on all the time because it drains the
battery.
On my Olympus 2040z, when I took a shot, it displayed the photo
while it was writing it to the SmartMedia, and then after that
displayed it for 2 seconds and shut off until the next picture was
taken. Is there a feature like this on the Nikon CP5000?