See the column that has "Coil Res" in ohms?
Anything under 5V/40mA = 125 ohm will smoke the arduino output pin.
As far as the contacts for the power being switched, they do not matter, no more than they do for a manually operated toggle switch.
As you say, the datasheet is light on details. Try some switching with just an ohmmeter across the NO contacts, make sure you have the coil part figured out first.