I doubt William ever saw Nolan in his costume. What I find unbelievable is that local beefcake DILF Nolan Greyson doesn’t constantly consume a young gay teens thoughts. William would be thinking of Nolan so often there’s no way he doesn’t make the connection.

Well doesn’t have to be spies, just people that can be trusted with knowing Omni-mans identity. They could have just been staff at the Global Defense Agency that had their housing taken care of

considering that humans are not a physically impressive race

They would be breeders. Human/Viltrum hybrids are almost full blooded Viltrumites, that’s very useful for a society struggling to maintain its population