What I've done for several crossover stories is use an outsider's point of view - someone who knows none of the players and very little about what is going on. Case in point was a Buffy / CHiPS crossover in which all that any of the CHiPS people knew was that there was something a bit "off" about Sunnydale and that they had orders not to go there.
Of course this would be very difficult in the L&C universe after episode 1 because everyone knows who Superman is - they may not know him as CK, but they're aware that he exists and may turn up to save someone, destroy evil, etc., so if something did start destroying the city the reaction would be "Superman will save us" - a lot of the fear of the unknown disappears,
