U should not give up fury at 40 when lvling. Arms is viable but u dont sustain as good as a 2h fury warr - bloodcraze, bloodthirst. On top of this u can make the most use out of enrage by pressing x key right before you get hit to sit down for a 100% critt, proccing enrage. U could potentially have 25% more dmg at all times getting used to this. Also bloodcraze is going to occur everytime u take a crit so it will deffinetly be worth it