It seems like parts of the Earth-2 history were a little fuzzy due to Superman, Batman, & Wonder Woman never really having clear demarcation between their Golden and Silver Age incarnations.

Was there a Jimmy Olsen on Earth-2. If so, did he do anything notable? What about Perry White? If I'm remembering right, they established that Clark Kent was given the EiC of the Daily Star over Perry, correct?

Alfred died of old age on Earth-2, right? When did this happen? What, if any, relationship did she have with Helena Wayne? Batman & Catwoman got married in 1954? Alfred was still around for the wedding, wasn't he?

Did they ever go into detail about the circumstances of Lyta Trevor's birth? Or why so many of the JSAer all decided to have kids in the early 1960s? Was there some story that Levitz, Conway or Thomas retconned in there wherein the assassination of JFK reminded them of their own mortality or something? Or was it simply a byproduct of Thomas creating most of the members of Infinity Inc. in the early 80s, all of whom were about 20 years old?

Were there any significant differences in the histories of Earth-2 from Earth-1, aside from the existence of superheroes during the 1940s?

Thanks for the help!