Get some form of knockback resistance, either from IO or Acrobatics. Fire armor is pretty squishy all things considered. It relies heavily when leveling on Healing Flames, which can't be used while on your butt.
Other than that get Rage and Burn as soon as you can, target smart, and watch out for enemy groups that other brutes take for granted. Council, for instance, is largely laughed at... but for a developing fire armor that -recharge has a HUGE impact against your survival.
Also, SS post Rage is a much different beast than pre-Rage. A boost in survivability is on your horizon as you finally get to catch up to other primary's damage.
And, to be honest, the sooner you can fit the Fighting Pool (I think weave is a waste of end until you're ready to respec into a 'superbuild' where every percentage of defense matters, so stopped at Tough) and Hasten the happier you'll be.
Weight training: Because you'll never hear someone lament "If only I were weaker, I could have saved them."
I see a lot of good discussion here about final builds and farming builds but cant see anything about a leveling build for ss/fa. Would anyone mind posting some thoughts on that please or point out a thread that has some info? I have a level 14 (seem to be getting my butt whooped especially kb) and need a little guidance about this since its my first foray into a potential farming brute. Thanks much.