Now, p. 92 mentions that team earnings assume that you have a place for them to work. Does this mean I have to buy a cart & mule as a separate expense, or are they covered by the 2 'goods' that are part of the driver's cost?
you need to buy or rent or own one. the driver is only a professional staff member, much like a cook or Gardner you need to provide what ever it is they work with for them.