You could do the same thing I just did to help point you in the right direction. Go into Blizzard's source code and look at the Scenario Objective Tracker file.
https://github.com/tomrus88/Blizzard...iveTracker.lua
Code:
local scenarioName, currentStage, numStages, flags, _, _, completed, xp, money = C_Scenario.GetInfo()
local stageName, stageDescription, numCriteria, _, _, _, numSpells, spellInfo, weightedProgress = C_Scenario.GetStepInfo()
SCENARIO_COMPLETED
SCENARIO_CRITERIA_UPDATE
SCENARIO_UPDATE
I wasn't able to find documentation on those events to be able to give you any parameters.
As for "teammates head-icons", I have no clue what you're talking about so I can't help there.