That's exactly how they act. Even in Maryland. From your link:
Step 1: Report the crime to the police...
Step 2: File charges with a District Court commissioner If the police do not conduct an investigation or file charges, you may file an Application for Statement of Charges on your own with a District Court commissioner.
A District Court commissioner, a judicial officer, reviews the Application for Statement of Charges to decide if sufficient evidence exits to charge the defendant (the person accused) with a crime (probable cause).
Note the decision to file criminal charges is with the district court commissioner. The citizen can apply to the comissioner to file charges, but he can't file charges himself.
That makes them a “private” court system that serves at the will of the prosecutor.
No, because the prosecutor (or court comissioner) is a public servant, either an elected official or someone appointed by an elected official. Hence he is an agent of the people.
The District Court commissioner is part of the court.
The clerk is part of the court.
The prosecutor IS NOT part of the court, he may be a “party to an action”. It’s that old separation of powers thingy.
If paperwork is filed with the clerk of the court or the commissioner, AND THE PAPERWORK IS IN ORDER, the court must act. Regardless of who filed the paperwork.