The 146 RJ is the same as the Falcon. The reason for guarding the tiller to 80 kts is that Vmcg is 81 kts. If you lose the critical (upwind outer) engine below this speed, rudder is not enough to keep straight - you'll need some tiller. There isn't any connection from rudder pedals to nose wheel steering. Without engine failure, rudder is effective at about 30 kts and beyond.