FLCL is a world where change seems distant or impossible, and the sameness itself is stifling and a major source of conflict in the plot, as in Seinfeld.

Steins;Gate's protagonist's alter-ego Hououin Kyouma is a larger-than-life egotistical (comedy) genius which is analogous to Jerry when he's on-stage in the monologue segments of the show. But that same SG protagonist as his "normie" self Rintaro Okabe is crippled by self-doubt, upstaged by his own alter-ego, and would do anything for his friends, much like the version of Jerry we see outside the monologue segments. If you've seen the last episode of Seinfeld, the parallels between the two are a bit more clear. In Seinfeld, the past catches up with Jerry and the crew, and they cool their heels in jail as a kind of karmic payback or comeuppance for their years of prior shenanigans. In Steins;Gate, at a certain point the comedic backdrop lifts, the folly of Rintaro's ego and hubris is laid bare and elevated, and the karmic debt seeks its due via time and space.

Kyouma is far more of a Kramer than a Jerry Seinfeld. Jerry's the snarky straight man surrounded by oddballs, that role in Stein's Gate would probably be Kurisu.

Good point about Jerry being the straight man. I was trying to explore the difference between onstage Jerry and offstage Jerry and draw a comparison to Rintaro/Kyouma, but I don't disagree with your interpretation. I think if we bring in the sequels, Maho is the closest we get to a straight (wo)man foil to Kyouma's color man.