Typically I vape 3mg at 60w with a .18 ohm coil on a dual 18650 squonk. My question is with a 15w exilis snowwolf pod system what nic level should I be vaping and should I be using salts or freebase fluid. All advice welcome.
It depends on how you think you'll use the pod.
Nic salts usually come in strengths of either 25 or 50mg, although some places do carry lower strengths. If you think you'll hit the pod just every now and then, like maybe 3 or 4 times an hour, a high-ish level nic salt is ok - provided you aren't sensitive to the salts. I am, sneeze every time I take a hit, can't deal with it.
If you think you'll be more of a 3-or-4 hits at a time, then 10 minutes later, 3 or 4 hits, you could go with 12 or 18mg freebase nic, or salts at that same strength if you prefer. Salts have much less throat hit. If you're used to the throat hit of 3mg, max VG liquid, you might find 18mg 50/50 a little harsh. That depends on you, too, and how sensitive your throat is.
Some small or MTL devices will wick max VG ok, but some will do better with a thinner liquid, in which case you'll want to try 35/65 or 50/50.