Motion 2 doesn't have the full 3D transforms that can be found in Motion 3, but it does have the Basic 3D filter, which allows for X,Y,Z rotation of an image. The filter uses the center of the image as the pivot point, though, so if you want a non-centered pivot, just nest the image in a larger, fixed-rez layer and apply the filter to the layer. The layer is padded out with empty space so that its center is wherever you want the pivot to be on the image.
Please note that layers have been renamed to "groups" in Motion 3. Ah, how confusing all this can be to describe when the names are so generalized and generic.
1) Toolbar>View>Adjust Anchor Point Tool
2) Move object anchor point to a new position in Canvas
3) Inspector>Properties>Right click to bring up Parameter behavior Pop-Up>Choose Oscillate (leave default sine wave shape)
4)Adjust sine wave amplitude to regulate pendulum swing
That by the way takes about 10 seconds to do tops. Another argument in this whole Motion vs. After Effects debate, while the AE people are still downloading a "How to Make a Pendulum Effect" tutorial, we're already onto the next project!