No obvious weaknesses ... just incremental (and expensive) upgrades on every piece really. A tough spot ... or good one too as you are not restricted and can look for good deals in every slot.
........not having a weapon with lifesteal so you can use tough as nails to boost your armor;
Imho, this is very common (and expensive) mistake barbs make.
To put LS on a weapon, I would have to give up either (a) 92% crit damage on my EF, or (b) at least 100dps on my MH.
And what would I gain? 1200 armor from a TaN? Or Superstition? (my choice). Neither of those, or any other possible third passive, are remotely worth 92% crit damage or 100dps on MH. it's not even close.
I think if every barb did this calculation with their own gear, I think they would find that Bloodthirst is far and away the most effeicient third passive. The amount of "stuff' it allows you to get on your weapon easily allows you to make up for that extra armor somehwere else on your gear.