Drums in the back have gone as much as 150,000 miles for some. I sure wouldn't change them just to change them. Fronts also need changed when they meet the minimum spec or if your want to change them for some other reason like dust control, etc. Fronts have given most around 30K, but that can vary widely.
2014 EV Coupe 16,500 miles
2014 EV Cabriolet 6,500 miles
Other than color, does your smart look like the ones at the top of the page?
If not then yes it is a 451.
I believe models years for the 451 ran 2008-2015.
If you have a Pure with moonroof, leather seats and no glove compartment or no door on the glove compartment then you most likely have a former "CarToGo" ex-rental car.
I brought my 2013 in for front brakes. They replaced them but the still made noise. The shop had to order and install better quality rotors and pads and install them. You want to make sure they install good quality. It was an extra $70 for the parts but they sound great now. Good luck!