I'm trying real hard to understand what you're saying here but it's eluding me. If you're referencing that Souleater won't heal you outside of grit - the self heal from souleater is so negligible that it could never be considered part of anyone's real mitigation. Even outside of grit, with Dark Arts, the most I've seen my souleater hit for is ~3000 HP... factor in the 20% damage reduction from grit and now you've got less than a cure 1 on every third GCD! Amazing!
Storm's Path heals you regardless of Defiance/Deliverance, and if you're using Inner Beast for the self healing (and not the mitigation after you've used it) you're using it wrong.
Defensive cooldowns are as active as mitigation gets in this game - they are the only things you can actively activate in a battle to increase mitigation, but yes, you are right, they aren't REALLY active mitigation. I go over this in my thread which is a response to this one.