I am only two weeks into modding FNV, and I find the render window infuriating. When you drag the object, it is placed "somewhere" in 3D space, but nowhere I can predict. Usually the Z coordinate of the object is huge, that is, it is way up in the sky. The render window rotates around whatever is selected, and sometimes you may lose track of what's selected. One trick I have used (and again I am no expert) is to select the newly placed object in the object window and right click and select view. This should zoom the render window to show the object. *Maybe* this will be more useful or maybe not. Sometimes I select edit on some other object nearby to where I want the object to go, write down the xyz coordinates, and then type in similar xyz coordinates for my object. Don't place it inside.
I assume this will get less painful for me as I gain experience, but I agree it is pretty frustrating. One thing I wish is that there was a button like "linked references" where you get a crosshair, and the new object would simply be placed on top of the object you select. At least then it would be in the same room.