who pays for the security to keep business and people safe?
The business itself manages its own security needs.
All community members have a moral obligation to step in for those that are subjected to physical aggression against their personhood or property. The public defense is informal, yet it needs to be defined by a culture of self-reliance and good ethics.
It would help if more of society was armed, and with something other than ineffective civilian firearms nonetheless. An armed society is a civil society.