Double posting for great justice!
Fire Whirlwind is a terrible S power. The startup is abysmal. Anyone can just enter the backplane and punish with backplane
into combo of choice. Will beat pretty much everything if used to anticipate a jump-in. (Remember CPU Billy?)
Not sure about beating Yamazaki or Kim's S-powers though.
Any attempt to use it at point blank range is suicidal. If blocked up close, the move, like several other supers, will stop hitting after the first 6 hits are blocked. This is a unique trait of the game where a blocked super projectile will only chip 6 times, then can no longer hit anything. Other examples of this include Sokaku's demon S-power and Geese's Razing Storm S-power.
Salamander Stream is one of the better P powers in the game. It comes out quickly, has great invincibility, hits backplane, can be comboed into, and pushes the opponent to a safe distance on block. Just be aware that many characters can breakshot the last hit pretty easily.
Far standing
and
work in a way similar to Dictator's slide in SF games. Many active hit frames means that if the move hits early the move will be punishable on block. However, if you can time it so that the last active frames hit, the move will give a big frame advantage, leading into combo possibilities for the
version, as mentioned by Yor.