You can say the spell slows them down, but it won't do anything on it's own. Speed isn't a stat here, so it'd just be fluff. 

And, for traits. Sorry. A Trait can do one thing. Some attacks might be able to do one other thing, like Kai Lao's granting of the Awakened buff, and Kuchi Daisho's stunning, but most buffs only give one bonus. But your hot headed does about three or four. So you have to chose one, or buy off the additions with extra points. So, Hot-headed can grant 25% to their attack. That's the trait. The stead-fast, and the igniting would have to be bought of seperately. Like-wise, you'd need an additional trait to make Stead-fast more than a defence buff. Having all three of them, with Stead fast granting defense, immunity to Panic, and shaking off pain - not sure what you were going for here, since pain isn't really a factor, if you are out of hp, you collapse, if you aren't, you dont - all on a single trait is to much. So, Hotheaded would cost about 4 points all together, with another two points to give stead-fast the additional procs. (It's pain thingie and panic immunity). Same with the rest.