I do find these abilities to be interesting, but I also think it’s important to know where they would fit into the mix. As our dearest @LordRhinark mentions: are these Traits, Properties, Talents, built-in passives?
While I like the idea of Superior Guard I think that one would need to be a trait due to an inherent Damage Reduction; the reason I’m afraid to stick it elsewhere would be because it would stack with other Damage Reductions as applied by Ironbreaker and Barkskin. Can’t be a property and wouldn’t exactly fix “All Shields” if it were a talent (unless the talent were available to all Kruber/Bardin careers).
Counter attack, or the concept of it, has been implemented in the way of Off Balance. When blocking an enemy, that enemy takes 20% increased damage for the next few seconds. I think it works similarly but doesn’t allow a wind-up. I’d prefer shielded weapons to stay away from ever being considered “boss-killers” so that they have a defined weakness.