regem your pants and chest. It's a common misconception when people say "gem +12 stam socket bonuses" What should really be said is, "Gem +12 stam socket bonuses that only require 1 hybrid gem."
By gemming your chest and legs with hybrid gems instead of all stam gems, you're really gemming for 2 +6 stam bonuses. If you do 3x30 you get 90 stam, as it stands you get 30+15+15+12 = 72 stam, for an 18 stam loss per item, not a 3 stam loss. I'd say regem your chest and legs, put 18 stam on your shield and gloves (or 240 armor to gloves). The other gems are fine.