Improved Ability Boost needs a cap or you've got barbs with +14 Str running around.
Aligned/Energy/Flurry/Natural Attack might work well together. A 2HF Barb will be sticking to IAB though.
Wild Fury isn't much of a defect. Make it mandatory or just forget it, since a raging Barbarian will rarely go "hey, I want to waste a turn of my strength bonus, go-go Combat Expertise!" Swift action spells can be useful, but I don't think it's a big deal.
I'm not sure defenseless even is really a defect (go go +16 Str Barbs!) but at least the -2 AC will hurt a bit at low level. No issue by high levels, though, a barb'll be getting hit anyway.