While boiling (100C) to freezing (0 C) may seem extreme, in terms of stainless steel those temps are quite pedestrian. To anneal stainless steel, you must heat it to at least 1000 C! Also, for concerns about the quenching, stainless won't warp or spall for a 100-0 C temp change
Don't be afraid to use the non-stick pan. If you don't wish to use Teflon, try cast iron. I always blacken in a cast iron. Now for steel:
1. Hot oil, ~380 - 400F
You should be using 1-2 Tbl fat in a 10" skillet for this. If you prefer butter, be sure to go 50/50 :: cooking oil/butter to increase the smoke point. Also, some fish are just difficult to pan fry. If all else fails, don't be afraid to dredge the fish in a light seafood breader before frying.
note: I've used the above technique to prepare a parmesan crusted tilapia in an aluminum pan - it can be done.