I'd also guess that the vast majority of deliveries are in urban areas as opposed to rural ones (in Germany at least), so it makes sense to prioritise that.
Even more so if for all of the foreseeable future, nothing is keeping you from operating conventional cars in the outback. A large fleet, a well established distributed depot infrastructure, a very predictable route schedule focused around a few hours of each day. Perfect match for EV early adoption.
Not exclusively. It seems to depend on the neighborhood. In some neighborhoods I've seen them using Renault Kangoos, which have a similar size compared to the StreetScooter Work.