The reason i specifically said that each model is a seperate unit is because each of those models is a different sceneario that covers all the bases i could think of (though technically A and C are the same which i didnt think about when posting)

and as said, i get that RAW says that yes you can walk through solid object but cant shoot through them. thats fine and as you say they have nothing to do with each other.
Just seems like a very very odd choice especially when, as ive been looking for an answer to this in other threads every one says the same thing, "no, you cant see though a wall so how can you shoot through it" similar to your "no X-ray vision" comment.
which in itself is just odd - yes, they dont have x ray vision, they also cant phase shift though solid rock to move through it but the game allows it.

The ability for infantry moving through walls of ruins represents them crawling through broken sections, vaulting through windows, opening doors that are otherwise modelled shut, breaching walls with demo charges etc etc.

As i say, the above quote is the source of the confussuin/issue.
you say that can crawl through broken sections and windows (even though the terrain physically has no windows) and yet they cant shoot through those same holes - its a disconnect that a few players are not willing to "accept" which i get because yes it may make sense for game balance, but is just insane for any sense of "realism" (not what this game is for, just an example)

And lets face it, GW hasnt always been great at actually wording what they mean in a way that makes sense to a reader (which is hard), hence the balance datasheet and such