Hiring private security versus the police for security at my bar/restaurant?

Can I hire the local police and have them stand over my business instead of the security companies that we use?

What are the rules for hiring police to do security instead of private security?

Also if I hire police do I eliminate the lawsuit threats that occur when private security is alleged to be too rough or overstepping their bounds, etc.?

No. You are legal for the actions that they do or cause. The security may be a better bet since LE can become rougher sometimes with your clients