#1.) May or may not work; I haven't confirmed it yet, but as someone who uses platemail I can see enemies still getting fairly stout crits occasionally, may need looking at? EDITED: This one does work.Critical Abatement II: Stalwart armor reduces the impact of critical hits you suffer while in combat, reducing their effectiveness. (Reduces Sustained Critical Bonus Damage 30%.)
Corporeal Fortitude II: Your choice in heavier armor has afforded the benefit of being less susceptible to incurring bodily injuries upon knock-outs. (Reduces Chance of Injury 30%.)
Focused Vitalitism II: The mental assurances gained from your armor choice affords you a better ability to regain your breath and corporeal vitality. (Increases Natural HP Regen 20%.)
Ranged Deflection: Simply due to the sheer design of the heavy armor that adorns you can, in rare circumstances, cause ranged attacks to be completel deflected, harmlessly skipping across your armaments like a rock upon water. (10% Chance to Deflect Martial Ranged / 20% Chance to Deflect Ranged SWM (Special Weapon Move).)
Juggernaut: The mental effects of feeling nigh invincible in such heavy armananets can sometimes sway the course of battle, emboldening the heavy armor user in the midst of battle. (20% Chance to regain 20% of received damage (after resists) returned as stamina and hit points: can only occur once every seven seconds.)
#2.) I can confirm Koss does appear to get injured less than others, but that may just be my play-style and just avoiding getting KO'd. Against certain foes it does still seem about what you'd expect in terms of the foes' Deadly Rating.
#3.) Pretty sure this one isn't working; its sincerely hard to gauge; at least it doesn't show up in [regenrates.
#4.) 100% Functional.
#5.) Does not work; I have never noticed or seen this proc, and im entirely confident i'd of noticed.