High level present in a pin of a non-powered IC can damage it?
Absolute Maximum Ratings indicate limit that will not cause any damage to the device, but don't mean that it will behave properly at those limits. Most devices have clamp diodes for ESD that can allow a voltage at any pin to unintentionally energize the device.
  The datasheet says 


  To ensure the Hi-Z state during power-up or powerdown periods, tie OE to GND through a pull-down
  resistor. The minimum value of the resistor is
  determined by the current-sourcing capability of the
  driver.


so I'd guess that so long as this is observed, the chip should behave as intended, i.e. do nothing with an input while not powered. 

You do need to take care that there are no loads on the Vcc lines that can draw current back through the protection diodes.