My coaster brake works great if that's a concern of yours. Regarding that priority, I wouldn't have a commuter without fenders, and belt drive seems like a gimmick to me. Chains last a long time on a single speed and they are super cheap to replace. I have another
bike with drum brakes, a 3 speed IGH and dynamo lighting that would be an awesome commuter, but I don't like leaving nice bikes locked up outside. I run a waxed chain on that one so I don't need a chainguard.