Did you seriously just argue that "if this decision has the potential for extreme negative consequences, then it must be a good decision"?

That scenario is from the dissenting opinion of justice sotomayer in the pdf brief. Trump's lawyers argued that immunity extends to assassinating political opponents.

Source?

It makes the president a king. If Trump gets reelected do you think he will ever leave office? If you think that's far fetched then you haven't read Project 2025 where he can replace weather service employees that don't make forecasts he likes.

Short of a civil war, yes, because the text of the 22nd Amendment is unambiguous and requires considerably more process than a supermajority in the House and Senate to overturn.