And as I said, at best all that would be talked about in the offices is how much he looks like Supes. I'll expand on 'why' in a second.
Superheroes in the context of the comic book world, ARE the celebrities. In fact they are the ultimate celebrity. They're in the constant eye of the public, are revered, and are held to a greater (or at least abnormal) societal standing. It's absolutely logical to draw the parallels to our own world. Be it Eminem, Michael Jackson, Oprah, Angelina Jolie, or whomever, these names have a face to go with the fame. So even if we only have a glimpse at their private lives, we draw the conclusion that they may go about as "regular people", but in no way are they leading a whole different identity. The whole dual-persona trope is carried about by superheroes who are in hiding. When you have no mask then (conceivably) you are in plain sight. That is why you do not group Supes with the other heroes.
Celebrities do not have super-powers, so no one could theorize that they could pull off a "Clark". Celebrities/famous people cannot fly or run very fast. Also, they don't need to create a secret identity. Technically, they are beloved people who don't need to protect themselves or their loved ones like a superhero does. No Super-Villains are going to want to get revenge on them for foiling that bank robbery, etc. The media won't stalk them about political issues at their house at 3 AM, or go to their work to ask for the celebrity to save their cat. Celebrities need the standard stuff, and as such, can go on living their own life. Superman would be harrassed all the time.
When you have a God who can do all sorts of things, a lot of posibilities are left open. Just because he doesn't seems to have a secret identity does not mean he doesn't have one, or that someone wouldn't start wondering about these things. Someone like Lois, who is terribly infatuated with Superman...And spends all day with him....I mean, with Clark...
George Clooney hanging out on a yacht is still Clooney. Someone who looks exactly like Clooney giving me my change at the supermarket is some guy with lucky genes. People could rag on either one, multiple times about that resemblance. What are both gonna say? George will laugh it off and wonder why such a ridiculous question is being asked. Fake-George will brush it off and tell you he gets that question a lot. What then? Well, nothing. The investigation stops there. If both are seen by peers and friends as routinely carrying out regular lives on a daily basis, you have nothing to go on. It's a goose chase.
Um, no it doesn't. It's one thing to have a resemblance to a famous person, which happens all the time. It's another to look exactly like such person, and have personal connections with the same people (namely, the Daily Planet staff) to boot. Also, Superman is an
alien. He looks human, sure, but no one could possibly look like him without turning a few heads.
THAT is the crux. Both Clark and Supes need to be displayed as having complete, separate identities. The look is second priority. You're right, Lois and the rest of the DP should be the most keen on figuring it out. But not if they have no reason to be led on that path. If Supes only comes out 5 minutes each day to perform a rescue and Clark is there the rest of the day doing paperwork, ok there's something fishy. If Clark is hard at work as a reporter all day long and Supes is seen all over the world keeping occupied, the illusion is safe. NO ONE will bother to pick apart two seemingly active identities. It goes against all logic and reasoning. I challenge anyone to argue otherwise.
You keep on ignoring Lois and the rest of The Daily Planet gang's real importance. Clark and Superman hang around the same set of people all the time. Take the Lois/Clark/Superman love triangle. How could a person not tell the difference?
Clark looks exactly like the alien Superman? Something fishy there!
The look is first priority because surely someone who isn't blind can tell they are the same guy. Also, no one has to "figure it out" right away. But if they start noticing things, then questions start being asked, and eventually someone will photoshop a picture of Clark, remove the glasses, and discover Superman. You're assuming that if both identities keep busy, no one will notice, but the people around Superman and Clark
would notice, and unless he mind rapes them like in Superman II, the disguise is f***ed. Superman/Clark have the same friends/love interests. Not all of them are ******ed. That is the problem. The rest of the world doesn't matters, but it only takes one person. Also, Lois, who is practically his press agent, could theorize that someone like Superman would be able to pull off a Clark and be in two places at the same time. She is just curious like that.