Let me try at it.
My understanding of that set is that it does not enhance stamina based abilities. I may be wrong, so wait until it is confirmed or not.
Weapon enchants have in internal cool down of 6 seconds. If you use the skill consecutively, it should not proc 100%. If you use the skill with 6 seconds in between, it may happen (the perils of RNG) but will not be the rule. I do not know the exact proc rate but I believe it is around 30%. It can be improved though.