Again I agreed with America should never have gone to war,
That's not the subject.
why wouldn’t Iranians be happy that a man who killed a million Iranians,
First, in the Sacred Defence Iran gave around 280.000 martyrs, not a million.
Second, the USA regime was threatening Iran with military aggression (more intensely than usual, that is). Thus Washington's illegal occupation of Iraq was not welcomed at all but explicitly condemned by Iran. As a consequence, Iran supported Iraqi Resistance groups fighting the occupiers.
injured probably just as many be happy that saddam was taken out of power and hung by their Shia brethren in Iraq someone who was responsible for killing my family and friends I would definitely be ecstatic.
To begin with, Iran does not view geopolitical events through a sectarian lens.
And in response to the quoted example: if a far more dangerous, able and skillful criminal came to eliminate the person responsible for killing one's family and friends, and settled right next to one's residence while threatening one with murder, no mentally sane person would feel "ecstatic".
But again you didn’t refute my comparisons between Kurds who attack Irans soil and Iran defending their right to attack them, same as America did with the Taliban you can’t be a hypocrite and say America had no right, they had every right and all the proof before they struck unlike Iraq, Iran also has every right to attack those who threaten to their people as well.
Because it's not related to do with the discussion at hand.
The USA invasion of Iraq was doubtlessly illegal, as confirmed by the UN Secretary General. No proof was presented by Washington for the presence of WMD in Iraq at that time, although the neocon USA regime cited this cock and bull story to spin a baseless casus belli against Baghdad. So I'm not sure what you wish to prove in this regard.
Also you didn’t refute Iraqi Shias who are much better off without Saddam and inshallah they work together to make Iraq a strong nation
That's a highly relative notion. As per a study conducted by The Lancet, a respected medical journal, Iraq lost 1,5 million people as a result of the illegal USA invasion, i.e. several times the number killed by Saddam's regime (not to mention the hundreds of thousands, mostly Shia Moslems, who died as a result of sanctions imposed on Iraq by Washington in the 1990's). Post-Saddam, Iraqis (Shia Moslems as well as smaller religious minorities in particular) had to suffer the savagery of "I"SIS.
Hadn't it been for Iran's help to the defenders of Iraq, mass graves of Iraqis in general would have mushroomed to a much larger extent because of Washington's criminal, instability-inducing and violence-provoking policies aimed at wrecking the Iraqi nation and state.