1. I feel vindicated for my comments about making Earth uninhabitable to the Daxamites by poisoning the atmosphere. I am not positive but I believe it was with lead.
2. On the subject of being able to see through lead. Trying to describe a real reason for not seeing most things through lead. I am quite sure both Superman and Supergirl can see through lead, even thick lead. The problem is what would they see. Assuming the xray vision is similar to real xrays, most of the rays are blocked by lead at levels such as used for medical diagnosis. Most not all. The problem becomes the only way to really see something on the other side of lead with xrays is the material must be denser than lead. Otherwise the sensitivity of the viewer must be very very extreme to pick up the fine nuances of whatever is so heavily shadowed by the lead material. It is sort of like if you were to have a fish tank filled with water and drop in some diamonds. They become almost invisible because the refractive index is almost identical to water. So except for very thin lead foil or maybe lead plating, the amount of energy of the xrays required to penetrate would completely pass through the what is on the other side unhindered.
3. Super hearing, in no way should lead affect the hearing. I do not know the thickness required for the sound to be completely damped to levels that it cannot be heard but the hearing of Superman and Supergirl should be able to hear a pin drop inside a recording studio if close enough to the studio and assuming active noise reduction is not being used and very very well matched to actual sound.
4. In no way should lead be unable to be affected by "heat vision". From what I understand that is just a focusing of a beam of "heat"/"light" like a laser. The lead should melt as fast as any other substance with a similar melting point. On the subject of heat vision, the battles where party A shoots beams of heat at party B who shoots back and they meet in the middle canceling each out. I believe that would only be possible if the amplitute and frequency of the emitted light/radiation are perfectly opposites of each other, like with active noise reduction. Otherwise I would except the beams to pass through each other with some points amplifying becoming warmer and some suppressing becoming cooler until they strike both parties eyes. The decree of change in temperature would depend upon both the degree the beams are synchronized at each point and the amplitude of the beams at each point.
5. Wynn saying I love you to Superman, I suspect is completely asexual in the same way one might say I love pizza or music or Steven King books. Winn has at no time shown any homosexual tendencies and has in fact been geeky heterosexual even to his girlfriend. He reminds me of Lewis Skolnick in Revenge of the Nerds.
6. I just realized, Monel is being called Monel. He was in the comics given that name by Superman/Superboy (2 different stories) because he (they?) thought he was their big brother. The name was Mon-El as in Kara Zor-El and Kal-El. The El part was the family name of Superman's family.