The lens manuals for my lenses without "full-time manual focusing" warn not to use the focusing ring when it's in Auto-Focus mode. I assume that even applies when the camera is off, but am I being too paranoid? A common use case is to compress the lens to its smallest size when packing it away. How bad is this really?
(Edit) My camera is a Canon T1i, so no in-body focusing motor. A friend has the XTi, also without an in-body motor. I've seen people be pretty casual about "shortening" their lenses in order to fit back into their camera bags. I've also seen people pick up telescoping lenses by the exposed (extruded?) portion of the lens instead of the normal zoom/focus part of the body. At what point are we risking harm to the lenses?