here's a plot hole that I never understood. If the Zerg can infest Kerrigan with all her psionic abilities, why can't they just fold her DNA into the swarm and make multiple kerrigans? that's what the zerg do right? they take abilities into their own and then replicate it.
what i really want to know is what the zerg were doing to her inside that chrysalis. Judicator Aldaris did say she was infested to the core