Unlees you can get some documentation that says the rear rack is suitable for passenger duty, and carry it with you, there's a very good chance some "shiny buttons" constable is gonna ticket you for "2 on a bike" Some foot pegs would be good for that too.
It's pretty crude bit of kit, but that's what it's meant to be, 40 lbs, one piece crank, straight tubes, should be a tough bike.