If a skill "does not stack," is that only with itself or do multiple, separate DNS skills not stack with each other, applying only the max buff? For example if I get +30% damage absorb from one skill and +20% from another. Do I now have 30 (max)? Do I have 50 (add)? Do I have 56 (times)?

Thats a good question actually some clarification on that would be nice!

As far as I have been able to tell many of the items, stat boosts and abilties pertaining to absorption, armor and defense in general dont work anyway. They have simply been disabled for some reason.

Shooting a dead eye with or without armor and a tanked out melee class with or without armor if they are standing in a defensive aura or not will do same essential damage. I use a las sniper for many of these tests. You get 50 - 56 all day.

Maybe im wrong here. Does anyone else have any information on this?

And if a skill does not stack then it will not stack with itself i believe. But you should be able to stack it with other skills if im not mistaken.