You won't blow anything up using a Protank with your new Nemesis. IMO 1.8-ohm coils are better on a mechanical mod. With 1.8-ohm coils you would be vaping at 2.3 amps (assuming 4.2 volts which is the battery right off the charger) or 2 amps at 3.7v (which is what your batteries will drop to pretty quickly). You would be at a very safe amperage, well below the limits of even a standard Efest battery and the 1.8-ohm coil will give you more vapor than the 2.2 ohm coils.
If you think that you will want to do any sub-ohm vaping in the future, you may want to invest in better (30a) batteries that will safely allow much higher current draw.
If you think that you will want to do any sub-ohm vaping in the future, you may want to invest in better (30a) batteries that will safely allow much higher current draw.