Now, you are reporting something entirely different from your first message, which was about textures (yet they didn't had anything wrong), now you are discussing polygonal shapes, but I stil don't see anything wrong with your screenshots.
The wheels of jetways surely don't have have a cubic shape in your screenshot, you can't obviously expect being perfectly rounded, they are obviously made with as few as polygons as possible in order to save fps.
For everything that seems to be hanging in the air, as discussed many times already on the forum, it's never a problem of the scenery, but is caused by another scenery (AFCAD, usually) in conflict that set a different ground altitude. In this case, use the free FSX Airport Scanner program to find AFCAD duplicates for an airport.