> Do you feel the same way about plumbers?
Obviously plumbers don't enforce the law, manage evidence, write legal documents or have legal authority over others. If you can't see the difference in power dynamics between a police officer or lawyer and a member of the public I cant help you.
You're making my point for me, of course police need all of the skills you have listed (except maybe 'how to project authority', whatever that means). All of these skills should be taught to them by other police, while they are learning the job.
They also must know the extent to which they are allowed to use their authority, the situations in which they can use lethal force, the appropriate evidentiary and legal processes for taking a case to court.
If they learn this on the job then they are risking making process mistakes, or falsely enforcing the law, or breaching rules of evidence, all on real members of the public.
They should be educated in all of these things and the limitations of their power BEFORE they have access to that power.
Education in Justice is not going be focused on contract law, and I reject the assertion that a beat cop doesn't need to know anything about securities fraud. You don't jump in at detective, most police are going to start working the streets and then move to different roles.