Correct. But there is the visual impression that they are all checked by default. I could see a less savvy user clicking on them and them selecting "ok to selec

Correct. But there is the visual impression that they are all checked by default. I could see a less savvy user clicking on them and them selecting "ok to selected" thinking "well, I deselected the rest of them", due to the difference in background between necessary and the other three buttons when selected. Maybe "nasty" was a bit hyperbolic, I will admit, but it has the potential to be confusing.