Hello,
Your description of the problem is a little unclear. You are saying things that have elements of a few different issues that are unrelated to one another.
But you did say "
We are talking about wireframes here, by the way". So I will start with this one.
1) If you are seeing this issue only in wire frame. One way to test if the solution I am about to lead you to is a good fix, is to render your scene twice; First with RTO ON, and secondly with RTO off. If you see holes in the geometry of some or all of the objects you will want to read the following threads:
The Solutionhttp://www.planetside.co.uk/forums/index.php?topic=14664.0There are two other threads on this problem but I could not find them even though one is mine. Anyway the thread I posted is the only one with the solution... If this is the problem you are having.
2) Another problem that sounds like some of the things you are saying has to do with the object its self.
If when importing an object the object does not appear in the 0,0,0 OR, does not appear at the coordinates you have input. But the object does appear in the scene. It is likely that the object's "pivot point" (The exact center of the object if it had a cube around it.) Is its self not at 0,0,0. The only way to fix this is to import the object into a modeling program and move the objects center to or near, 0,0,0 in the XYZ.
One way to test this is to scale the object down very small and put it on the ground right in front of your camera. If it then appears where it should, but does not at a large size, then this is the problem.
This happened to me a lot when I was first learning to model. I had objects that were very difficult to work with because they were not centered properly.
I think there could be some other possibilities too. Please clarify the problems you are seeing. A screen grab may be of use.