layman terms: Lengths of not more than 6 feet from an outlet
As the cable flies

Length limits on cables and cords in the NEC are measured in the length of the cable or cord you need to get there by the most direct route.  Keep in mind that instead of type AC (nee BX) cable, you can use type MC cable instead.  (In particular, I'd do some research into what's generically known as a type MCI-A cable -- these are basically a cross between AC and MC that beats both of its parents on most things.)

Outlet != receptacle

An "outlet" in the NEC is any point where the house wiring stops and other wiring (cordage or utilization equipment whips) begins.  Receptacles are simply devices that make outlets convenient to use -- an outlet under the NEC for a hardwired appliance that's not in yet will simply be a junction box with nutted-off wires tucked inside and a cover slapped on.