- Batman must have lined his utility belt with lead, which would explain why he was able to keep Kryptonite in it without Superman noticing. It makes sense since Batman was also one of the first people to figure out that Kryptonite emits a small amount of radiation that is also fatal to humans after prolonged exposure, so he probably did it (initially) to protect himself. This is further backed up in the episode, "Knight Time" when Superman had to masquerade as Batman, and Robin had to tell him which compartment in Batman's utility belt that the grappling gun was located. Superman, having x-ray vision, should have spotted it unless something as dense as lead was blocking it.
- When you think of Jor-El's plan to save Krypton, it's downward chilling: Put everyone in the Phantom Zone, then once Jor-El travelled to Earth, he would release his people. Two words: Alien Invasion.
- Also remember that The Phantom Zone is where the most vile and evil Kryptonians are imprisoned. This could have been a fate worse than death for many innocents. Its no wonder why the Kryptonian council rejected this.