Unless something has changed since I few the MD, the autothrottles start their power reduction at 47' AGL. The voice callouts are a subtle but an effective cue as to the rate of descent at that time. A rapid 50,40,30,20,10, would be indicative of a impending harder that desired landing. The AT retardation is easlily overridden IMO, and in and of it's self should not be a factor assuming your hand is on the throttles to begin with.
I do not reacll any specific AT guidelines for not using the AT's during crosswind landings. Maybe someone here with more recent time in the aircraft can correct me on this.