1. How Many Know Of Kal-El's Existence?
This is probably the most important question we've got to ask ourselves with Man of Steel being part of a much bigger universe. As far as we know only earthlings and Zod's men knew of Kal's existence after Krypton was destroyed. From what we know from the prequel comic as well as the info that we had in the movie, Krypton had a big impact all across the universe in many other species that exist in the universe the movie is set it. If there's something I can be really sure is that the destruction of an entire planet, not just a planet with that is just starting or one with moderately smart life forms (like earth) but I'm talking about a planet that colonized hundreds and millions of solar systems, who were one of the most prolific races in the entire universe, something like that would cause huge repercussions among different species. Now, imagine if one of those races finds one that there's a survivor of that planet. Not only that, but that he's now completely grown and that he has amazing capabilities that no other Kryptonian has ever had before. This could mean 2 things and all depends on whether or not those races were friends with the Kryptonians or enemies. Many storylines can come up from something like that, it will be very interesting to see how they could manage something like that if they plan to include the Green Lantern Corps on the current continuity. Like I said earlier, those questions could raise interesting answers, and it will be really cool to see them developed by the writers. Let's hope that if they do explore them, they do the proper work with them.