Well I won't modify this build by touching CON as I'm not sure where I should take the points out - but that's not an issue, I can start as a 2 hander and respec using this build once I have Stalwart Defiance (and Sanguine Plate I guess), or try this build right from the start by using some of the suggestions you gave in this thread.
Two more question: I'm going to make a party using some of the npc companions I haven't used yet, basically Pallegina, Maneha and Hiravias, and I will also hire a ranged priest. How could I use these classes and their abilities/spells to complement my barbarian? Keep in mind that I never used paladins and barbarians, so I know nothing about them. Also what class should I hire for my sixth party slot?