Thank you for the advice.

I have heard of "parser" but I don't really know what it is for sure, and I think it is a 3rd-party program or something. I don't really want to use anything that could get me in trouble. Better safe than sorry. (Just how I feel).

Yes, I keep Huton up and keep Shadow Fang Applied, and Mutilate if I think the mob isn't going to die soon.
Armor crush on the flank and Aeolian Edge from behind.

I keep Dancing Edge up, but I still sometimes use it by accident even when a warrior is present.

I'm not sure which is better for 4+ mobs; Katon or Doton. I usually put down Doton first, then use Kassatsu and then Katon, but not sure if it optimal way.

I always use Raiton for Single Target, unless boss and Trick Attack is available. Then, I use that first.

I am still getting used to the timing of Duality and Dream within a Dream. Should I save them for after I've used Trick Attack? Or just use them whenever they are up?

I have never been to Stone Sky Sea. Do I need to go with a party?