Jett17, first of all even though the N2 is a 0.7 coil, my sense is that it can be used MTL with the right airflow and wattage, or even a restricted lung hit. If you are using that coil, due to space and size, it functions a bit differently (IMO) than a typical sub0hm coil. You need more PG for juice flow to be easy, depending on what you got from the vape store, but you can still use a fair bit of PG in your tank. That might help stop the dry hits, and also, up your nicotine significantly. At LEAST 12 nic, maybe higher. If you are having trouble with wicking still, you can draw air in to the tank a few seconds after you finish pressing the fire button, as it's a small tank, with medium at best airflow, that may help your wicking be more consistent. I use MAX VG in that tank, (I'm pg sensitive) and doing it that way avoids any dry hits for me (in any of the coils). I don't really consider the 0.7 sub0hming, and just because a coil is slightly below 1.0 resistance, that doesn't automatically make it not a MTL tank, or at best, a restricted lung hit, due to the design of the tank (in my opinion). I don't think your gear is at issue here, either, I think you need more nicotine. I like the Nautilus 1.6 coil a lot, it's a nice balance between the 0.7 coil and the 1.8. Either one is still going to be more powerful than you might be used to with very old gear, so why the shop sent you home with 6 mg nicotine e-juice is beyond me.
Just my 02 cents, I do have a lot of experience with that tank and those coils, however. Best of luck, and I really think that if a true sub0hm tank is "too much" you can make the N2 work well for you on the 0.7 coil. Welcome back to ECF.
Anna