Do fly-by-wire flight controls in airliners provide artificial feel?
After some digging, I found an answer for myself: yes, some FBW airliners use artificial feel systems, but not all of them. According to Electronics in the Evolution of Flight (Google Books),


  The [Boeing] 777 fly-by-wire system employs envelope protection. This feature of the artificial-feel system provides increasingly greater force when the aircraft is pushed to its limits.


Conversely, Airbus does not provide any feedback to the pilots as their flight control system enforces control laws that cannot be overridden by inputs (source: Aerospatiale engineering document):


  The positioning of the control surfaces is no longer a simple reflection of the pilot’s control inputs and conversely, the natural aerodynamic characteristics of the aircraft are not fed back directly to the pilot.




Getting regulatory, since I did some further research: 14 CFR 29.395, certification of Transport Category aircraft, only states that the controls are required to resist a certain amount of force (i.e., not break). This differs from how much force is required to "achieve the positive limit maneuvering load factor" or otherwise impart changes to the aircraft's orientation (14 CFR 23.155 / 23.157).