As it turns out, part of maintaining that "public support" is not taking advantage of it. The very idea of a stable monopoly on violent escalation is obviously meant to deter violence. When it instead makes violence more likely (because the monopolist is suddenly planning to abuse its monopoly) that's quite a big change and people can be expected to react accordingly.
That is correct. It really depends on the temperature of public sentiment .
Many protests get a charitable assumption in the US as a legacy of civil rights and the Vietnam anti-war movements. However, I think a lot of that good will is eroding.
Each country has different perceptions, and ultimately, each protest is different (e.g. who shot first, is it abuse, ect)
Governance is maintaining public support for the government having a monopoly on violent escalation.
If the government does not have this power, then any person has an individual veto over the rest of the country.
Laws are used to describe how and when individuals can protest.