I am working on a house model and was planning on creating linked duplicates (Alt-D) of the inner doors. The problem I seem to have is that the rotation direction is different for the doors - some may open in, some out, some from the right, and some from the left. When I change the center (or rotation point) for one door, it changes the center for the other linked doors too and making the rotation of the other doors from the wrong point.
Is there a way for the linked objects to have different centers, or is the only way around this to actually duplicate (Shift-D) the objects and not have them linked?
Yes - kind of. You will have to use an empty. For example, assume you have created a right opening door, and you use alt-d and now want a left opening door. For the copy, create an empty and place it in what would be the hinge location. Now move the copied door to the correct location, and parent the copied object to the empty. Now when you rotate the empty it will be a left opening door.