There is absolutey no way that these two men could every possibly be the same character.
The mere suggestion is ludicrous.
Also, in all geekish seriousness, I should advise that Kal's disguise of Clark Kent is based not so much on blatant physical appearance, as it is on a projection of false character. Clark is portrayed as a bumbling doofus precisely so you never entertain the idea that The Man Of Steel and the somewhat timid City Beat reporter at the Daily Planet are one and the same.
Batsy pulls the same stunt with his Bruce Wayne shtick.
But, come on now. That build, those shoulders, that jawline; and the fact that Clark is never around when Supes is, and somehow always reappears right after the Big Red Boots flies away? Lois pondered this evidence at the tail end of the first Superman movie, but dismissed it only because she couldn't accept that the two totally opposite personalities presented, were in-fact the sole and very-same man.
First off, do not apologize about the length of your response. It was passionate and yet restrained and still quite civil. And for that you get props.
I recognize that we see this character from opposite ends of a somewhat seminal era in Superman's evolution.
I'll just comment that Superman has managed to make some terribly powerful enemies over his long career, and that there cannot be too much insulation between his Spandex activism and that other, relatively docile and domestic half of his existence. And so it is, that while a man with super-vision would not need glasses, it also helps that those who are observant and suspicious, would assert that a man who cannot open a bottle of beer also cannot catch bullets and missiles with his bare hands. Or that a man who trips over his words as much as he trips over his own feet, cannot stand in front of the world and deliver exactly the right speech for the occasion, with dignity and poise.
Kevin Smith's grudging acceptance of Clark's "disguise" should be addressed here.
Actually, one point of praise that Richard Donner gave to Chris Reeve's portrayal in Superman the Movie, is how Chris would hunch his shoulders and concave his torso to basically "shrink" his appearance while playing Clark, but then would allow himself to swell back out to his real measurements when in the blue tights. Watch the scene in Lois's apartment after the flying date, when Clark almost confesses his true identity, for the best example of this.