you still need a screw driver to mount the motherboard.
I used a magnetic screwdriver with no problem. I was very paranoid of touching the case when I was working even though it was in a hardwood floored room with a tile table. Can never be to careful.
As long as your not touching circuitry or parts with the magnetic screwdriver you should be ok. And the magnet is pretty weak. But if in doubt, find a demagnetized screw driver.