Sergeant: The last rank before a LEO stops being an officer. We always said anything above the rank of Sergeant is a politician.
No laws on the books that make driving an otherwise normal ORV originally manufactured as/for an ORV on a public roadway illegal? Of course, there are.
If a LEO chooses to pull you over (plated or not), just like they do with any other on-road vehicle, you'll need to produce valid registration and proof of basic liability insurance, again, just like with any other on-road vehicle. If there are equipment violations or deficiencies, just like any other on-road vehicle, you can be cited for that as well. And, yes, there are a number of situations where a plate can be confiscated and even destroyed (registration cancelled by SOS), most arising from misdemeanor offenses.
I'm not referring to ORVs being driving on the side of the public roadways up north, can't (legally) exceed 25 MPH, and must stay off of state highways or expressways. That's most of northern Michigan and da UP. I'm talking about a Pioneers, Talons, Razors and other ORVs bobbing down the middle of the public roadway like any other on-road vehicle.
Farm plates aren't related to otherwise normal on-road, registered vehicles becuase, unlike normal plates, there are usage restrictions attached to them. MCL s 257.801(1)(c) and 257.802(10) covers the issuance of farm plates, and that has to do with reducing the COST of the plate based on how the vehicle is to be used, and the law most certainly defines what the restrictions and usage of farm plates are legal for. Part of obtaining farm plates requires you to sign a 'Qualfiying Use' form (SOS-437) standing that you understand and agree to those restrictions.