It's about Kinetic Ward - successful shielding would additionaly trigger combat technique effect on the attacker (on a separate x-seconds cooldown maybe).
The problem is that your idea doesn't fix the *spikiness* issue. High spikiness occurs when you rely too much on the very chance based mitigation mechanisms that you're recommending be improved. This would actually *increase* spikiness by shifting more of our survivability onto our chance based mitigation mechanisms.
I'd also consider restoring 20% armor buff on Martial Prowess talent.
The 20% increase to armor isn't really going to do much. It'll amount to all of 1-2% total DR. Considering the difference between the passive DR of Guardian/VGs and Shadows is roughly 20%(Shadows top out at ~35%, VG/Guards top out at ~55%) and how *likely* attacks are to punch right through out chance based mitigation (~34% chance for an M/R attack, ~45% chance for an F/T attack), our incoming damage is *ridiculously* spiky, especially on F/T where we either take amount the same amount of damage as a VG/Guard or we take 45% more.