Maybe there are exceptions, and it probably depends on what the "something" is, but in general, I think I say "glance at something."

Sehe ich das richtig, dass "glance through" und "glance over" sich fast nur auf Texte beziehen,

Well, you can, of course, glance through a window (or a door, etc.) at something.

Or glance over your shoulder at something.

If the object of the preposition "through" or "over" is the thing being looked at though, I would say that thing is quite likely to be a text, which is being read, cursorily.

But probably not always. I could see myself saying "I was just glancing through the clothes on the rack" (in a shop), or using it in that way.

I think we should ask Martin--cal about your examples, they may use "glance at" in a non-literal sense more often than I do.

For what it's worth though:

glance at the new shopping center - yes, but this would probably just be the normal meaning of glance

glance at the assortment of goods of the new supermarket -   I think I'd be more likely to have a quick/cursory look through an assortment.

glance at the new generation of cars -

I cannot imagine how that would work. Too big for a glance. Not all in one place.

glance at the new president - again, that would probably mean literally take a quick look.

glance at the latest painting of AE procrastinator ...and glance away again, wincing in pain.

I agree with AE on most points. The first four of your examples seem fine. That is, I can imagine circumstances where you would say each of the four phrases (although "glancing at the new president" is somewhat far-fetched; -- perhaps in a crowded room at a reception.)

And I agree, it is harder to picture circumstances where I would "glance at" a new generation of cars. At a picture of the new generation, yes.

But I disagree with AE in that I could not see myself saying "I was just glancing through the clothes on the rack". I would say "glancing at", or "taking a quick look at", etc.