That's not much difference from a normal optimized charger using Leap Attack/Shocktrooper. Plus that would require, you know, walking around with only 100 hp as a main melee character at level 20. Good way to get killed.
Level 4 ability: Shield Specialization would be ok; I would suggest Armor Specialization, but that's redundant with Trust Your Armor. Maybe Improved Toughness as a bonus feat?