Whiskey Rebellion was before the Posse Commitatus act, and the perfectly lawful use of troops, mostly militia, was led in the field by President Washington himself.
Bonus Army action was shameful and likely illegal, but there were unintended results from what was supposed to be merely a crowd control action. I'd blame MacArthur mostly.
Kent State was national guard acting under *state* orders, where their use to enforce the law is perfectly legal and exempt from Posse Commitatus. (See Art. 1 section 8 which reads in part: Congress shall have the power ... To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions
Waco was Texas Guard equipment operated (mostly) by FBI, under false pretenses. (IOW the governor was lied to by the FBI, who was lied to by the BATFE).
That's all quite interesting. When the Clampdown comes, I'm sure I'll find it comforting that the GIs blowing my family to bits with high-powered military weapons are doing so in accordance with firm legal precedent.