Re: point 3, it strikes me that anyone manipulative enough to use "Do what I say or you're a horrible awful problematic person" will also be manipulative enough to use "Pointing out my emotional manipulation is tone policing!"

There's some kind of point (4) in this, along the lines of "Doing this muddies and devalues social justice as a whole, although those willing to do so may consider this an acceptable external cost of getting their way".