Can sleep paralysis or cataplexy kill me?

Absolutely not. Sleep paralysis and cataplexy are muscle weakness events while awake. This muscle weakness happen in a normal situation only during rem dream sleep. Cataplexy could cause falls, but rarely injuries.
Sleep Paralysis. Sleep researchers conclude that, in most cases, sleep paralysis is simply a sign that your body is not moving smoothly through the stages of sleep. Rarely is sleep paralysis linked to deep underlying psychiatric problems. http://www.webmd.com/sleep-disorders/guide/sleep-paralysis#1.