1. Her lightning is more powerful than any firebending lightning exhibited in the series. She can channel continuous strokes from the sky and from her hands at the same time. See her battle with Apocalypse in the finale, before she was turned into a horseman. She can overload opponents this way as well, like she did when she fought Apocalypse's advanced robots that had proved highly resistant to her attacks. She continuously struck them with lightning until they fell.
2. Her elemental powers are far superior to anyone in this group. She can make tornadoes, hurricanes and flash floods casually. Not to mention can fly. None of the characters in this group possess that sort of power under their belt. She would mop the floor with everyone here in a one on one fight and would likely solo them in a team.
3. Except you forget the fact that he has a weapon that allows him to create flames whenever he wants to. Storm took out his fire(which is much more powerful than Zuko's) and prevented him from making new flames, and then directed a lightning bolt directly at his weapon to disable it. Zuko is outclassed here.
4. Toph cannot detect airborne enemies unless they are making noise. She couldn't detect the wasp and needed Katara to guide her attacks. She couldn't detect Aang(who was jumping around lightly with his airbending). Storm can sustain flight far away from the ground and hit Toph with a number of attacks that she wouldn't see coming. She is outclassed here as well.
5. Katara would first have to see where Storm is firing her attack before she can try to use any water bending to absorb it. Unlike the characters in Avatar, Storm can command lightning. She can target it at her from any number of directions and overwhelm her with it. Not to mention Storm's winds would make short work of her water bending as well. She's used it to hold back a giant water spout, casually raise the water from the sewer floor and to manipulate water to defeat the thieves guild.
6. Aang is not a quicker and more maneuverable target than Storm is used to. She's dealt with close hand combat with Mystique and made short work of Toad(who has superhuman agility). Aang dodging Ozai's lightning is much different than how he would have to dodge Storm's lightning. She can fire multiple shots at the same time instantly from the sky and from her hands and easily blow him out of the air with her superior control over wind. Not to mention she can use her powers to work with the elements like when she formed a tornado around herself to effectively move at Quicksilver level speeds to take out an amped up Sabretooth. Storm has Avatar State level power that she can play with, so he is very outclassed without his to back him.