The chip protect the inputs because the parallel port is only dealing with known impedances from the IC. This is what is calleds a buffer. So the current taken from the port will be only the one stated on the data sheet of the IC. At the other side of the chip, where you connect your inputs/outputs you will have more current available, and if you screw up you will damage the chip and not the port, had the chip not been there. Now if you want to completly not risk it, then you would need to add on top of that, a opto-isolator :wink:
You can use the direction pin to control if you read or write. Or you could just hard wire it to always output or always read the pins.
Good Luck
Ivancho