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.