Questions about the Electrocution Skill (Sorcerer)

I have 4 points invested in “Electrocution” because it seems like great damage reduction, particularly as my critical strike chance is 100% and I can teleport almost at will. So for me it reads

Enemies deal 24% less damage for 5 seconds after being critically struck by your shock skills.

But I have questions.

  1. Does the boss do reduced damage to every member of my party or just me?
  2. Assuming the answer to #1 is “every member of the party”, then does this reduction number stack if multiple party members use the skill? Suppose two of us had this level of Electrocution and 100% crit chance and continually hit a boss with shock skills, is that boss now going to do 48% less damage to everyone?
  3. Does this damage reduction apply to things like ground effects caused by the boss?